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Guan, Sen. 2012.Fairfield Osborn Preserve Outdoor Autonomous

1. Power Batteries Batteries Source E f F Controlor Controlor E cl i Solar Panel Solar Panel Solar Power Solar Power System System Figure 12 The FOP Communication System Block Diagram 4 2 Design Details From the last sub section we learned that the FOPW is build up of three nodes and two solar power systems Each node contains different components and has different power requirements The following sub section introduces the details for each node and the solar power system as shown in Figure 12 Table 4 contains the detail specifications of each node The FOP design uses 2 4GHz radio and 802 1 1b g protocol to communicate with adjacent nodes The End Node uses 5GHz radio and 802 11n protocol to 35 communicate with end users such as sensors and computers In order to overcome huge propagation attenuation the FOP design uses 500mW transmit power and high gain directional antennas between adjacent nodes Table 4 Specifications of Each Node Nodes Office Node Middle Node End Node Specifications Mode Router Repeater Bridge Repeater Firmware D link DD WRT Hawking SSID Office Node Middle Node End Node Frequency 2 4G Hz 2 4G Hz Receive 802 11b g 802 11b g 2 4GHz 802 11b g Re transmit 5GHz 802 11n Channel Channel 1 Receive Receive Channel 1 Channel 6 Re transmit Re transmit Channel 6 Cha
2. seen 11 List of Equations Equation l Free Spaee Patli Loss 5 uses ever Rd trn ge uate eae eet ade ee eae 24 Equation 2 Fresnel Zone Determination 11 eere 28 Equation 3 Ist Fresnel Zone Radius 11 sese 28 Equation 4 Weissberger s Modified Exponential Decay Model 14 30 Equation 5 Estimation for the Number of BatterieS sssssesssrsrsrsrrssrrosersrrssrrsersrrsnrs 43 List of Tables Table 1 The Comparison of Similar Outdoor WLAN Designs eee 16 Table 2 802 11 Protocol COmpatiSOB eese inte tpa HE PTS reto porre add 22 Table 3 Solar Panel Power OUIDUE ies det I Peng ety Do rene PRSE EOdeo rr sens ES RN AEST NUR UE E DAR UN 22 Table 4 Specifications of Each Node sssssessressrrssrrrsrrressrrrrrrrsrrrsrrrrsrrrrrrrr sens enne enne 36 Table 5 Linksys WRTS54G Specifications s ssssesssrsrsrsressrersrrrrrnrerrresrrerrrrr rens enne enne 39 Table 6 Power Consumption for the Router the Signal Booster and the Repeater 42 Table 7 Solar Panel Angel Calculation 17 serene 44 Table 8 Middle Node Locations Comparison seen 49 Table 9 The Path Loss Comparison over The Links eene 50 Table 10 RSSIs in Different Directions a dede ae 53 Table 11 Network Performance in Different Weather see 55 Table
3. eene 26 Figure 7 Directional Antenna Beamwidth 10 sere 27 Figure 9 Eresnel Zone pL deeds ete f a eese ys d duc as Pots NOn Ee QU coc EE MER 28 Figure 9 Typical Solar Power System 2 24 eni cident dentate uisu Qu dodo puc 31 Figure 10 Sunrise Sunset Dawn and Dusk Times in FOP 14 33 Figure 11 The High Level Data Communication Design eee 34 Figure 12 The FOP Communication System Block Diagram sees 35 Figure 13 The Office Node Desierto treo Ua Cet beoe aod a aas 37 Figure 14 The Middle Node Design ssmsssssersssrserrsrresresersrresressrsrrssrrssrsrrs tai eae add 38 Figure 15 Linksys WRT54G COnfigUratiOl sesserserssresersrrssrrssrssrrsrrssrssrrsrrssrrr rr sr rna 39 Figure 16 The End Node Design ssssmsssrssrssrresresrrsrresresrrsrrssresrsrsrrssrrssrsrrs sees sr ss rr sr D s reser auus 41 Figure 17 Solar Panel Tilt Anple uuo ec pue antes octo Pere a eee 44 Figure 18 The Idea Installation 2 c 2 scascos see tot See FIO Eee ROS PN Rec ba oH Hp ise ada neces 45 Figure 19 The Wireless SSIDs Captured by InSSIDer 18 sesse 46 Figure 20 The Signal Strength Captured by InSSIDer as Shown in Google Earth Map47 Figure 21 Middle Node and End Node potential locations sess 48 Figure 22 Middle Node Reception Survey sodass n Eden aad
4. aL LU LU ILI 0 100 200 300 400 500 600 700 800 loop CU V Show Points 3 E Last Curve ernie OD rne Figure 27 Network Performance in Different Weather The results are shown in Figure 27 and summarized in Table 11 In the figure red lines indicate the response time of the communication between Office Node and End Node in foggy weather and black lines for sunny weather From the table we can tell that in foggy weather the ART increased by 50 and more packets dropped 1000 packets were sent from the End Node to the Office Node If the Office Node received the sending packet it sent an acknowledgment back Otherwise the packet was considered to be lost during transmission In 1000 loops 58 packets are lost in sunny weather and 108 packets are lost in foggy weather In rainy weather there is no connection between each node From the results we observe that the 2 4GHz radio wave has a poor penetrability in the forest environment in rainy weather When it is raining rainfall sticks on trees and leaves Water causes more absorption and reflection then dry foliage 54 Table 11 Network Performance in Different Weather Weather Condition Average of Response Time Packet Lost Rate Sunny 61 38ms 5 8 Foggy 97 95ms 10 8 Rainy Time Out 100 5 3 Power Consumption The power consumption is tested after the entire network was set up The Middle Node uses 5 1W without any traffi
5. 71 D4 Middle Node amp End Node Power Consumption Measurement Equipment Fluke 179 Multimeter Laptop Procedures 1 Use Fluke 179 multimeter to observe the current of the Middle Node when there is no data being transferred Record the minimum and maximum value 2 Connect Laptop to the Middle Node Start loading YouTube video Observe the current of the Middle Node and record the value 3 Repeat stepl and step 2 by connecting multimeter and laptop to the End Node Result Table 17 Middle Node and End Node Power Consumption Measurement Node Voltage No Traffic Loading Videos Average V Minimum Maximum Minimum Maximum Power Current A Current A Current A Current A W Middle 12 58 0 425 0 425 0 53 1 51 14 65 Node End 12 96 0 86 0 86 0 89 0 89 10 32 Node 72 D5 Environmental Impacts D5 1 Different Antenna Heights vs Signal Strength Test Procedures Use the same set up of End Node to broadcast signal 2 Holding a laptop walk away from the router 3 Record RSSIs along the walking path 4 Display RSSI data in to Google Earth shown in Figure 33 Figure 33 RSSI vs Distance Antenna Height is 3 feet 5 Repeat step 1 to step 4 by increasing the height of PVC pipe to 6 feet Result is shown in Figure 34 Figure 34 RSSI vs Distance Antenna Height is 6 feet 73 D5 2 Signal Strength vs Different Weathers Test Procedures 1
6. said Siyu Li 13 He believes that the speed of signal attenuation is not monotonically decreasing and the transmission range is not monotonically increasing with the increase of antenna height If antennas are set above the height of the obstructions it will be very 29 unfeasible and uneconomic Therefore Antennas are not necessarily to be set at a very high position If a network is set up in a forest environment it is very difficult to increase the antenna height to obtain a clear Fresnel Zone Equation 1 is not suitable in this situation In other words we need to create a model to predict the signal loss along the propagating path in a forest environment Many studies have been carried out to characterize and model the effects of vegetation experimentally Weissberger s Modified Exponential Decay Model 14 is applicable in situations where propagation is likely to occur through a grove of trees rather than by diffraction over the top of the trees In the FOPW design the LOS path is blocked by dense dry and leafy trees Therefore we can use Weissberger s model to predict the signal loss The expression is shown in Equation 4 which claims that the path loss must be calculated with inclusion of the FSPL Based on this model the 2 4GHz signal has an additional 0 2dB m 0 5dB m in a forest environment 0 284 40 588 Loss dBy o f d 14m lt d lt 400m 0 45 f928 x q 0m d 14m Where Loss Vegetation loss in dB
7. E5 HawkingHSB2 Signal Booster Data Sheet http hawkingtech com index php products downloadfile 37 html E6 USB Wireless Adapter Data Sheet http www alfa com tw in front bin ptdetail phtml PartZAW USO36EH amp Category 0 E7 Sunforce 50048 Solar Panel Kits User s Manual http sunforceproducts com prodinfo fr_vend_lit 50048 60W 20kit 20SF pdf E8 Power Bright PW400 12 Power Inverter Specification Sheet http www powerbright com pdf PW400_spec_sheet pdf E9 GPS Sensor Data Sheet http www usglobalsat com store download 62 bu353_ds_ug pdf 78
8. F 104 0 F Humidity Range Operating 10 85 Dimensions W D H 7 3inch 6 9inch 1 9inch Weight 1 11bs By changing the firmware into a third party firmware called DD WRT An indoor router Linksys WRT54G is able to perform as a repeater bridge The modification procedures are shown in Appendix C2 The firmware adds many useful features such as adjustable transmit power and the scheduled radio time restrictions TX Power 65 Default 71 Range 1 251mW Afterburner Disable v Default Disable Bluetooth Coexistence Mode Disable Z Default Disable Wireless GUI Access 9 Enable Disable Default Enable Radio Time Restrictions Radio Scheduling 9 Enable Disable Default Disable 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 mmmgmm X O HERE Figure 15 Linksys WRT54G Configuration Form Figure 15 the transmit power set up at 65mW 18dBm because of the signal booster requires input power from 8dBm to 18dBm In the Radio Time Restrictions setup menu the transmit radio is closed from 20pm to 5am of the next day By shutting down the radio wave transmission the Middle node can reduce power 39 consumption in a daily routine In order to build up a self sufficient system the Middle Node requires a solar power system conserve power in different weathers The solar power system includes the solar panels the smart controller and the batteries The solar power system
9. f Frequency in GHz d Depth of trees in meter Equation 4 Weissberger s Modified Exponential Decay Model 14 Another impact of environment comes from different weather conditions In different weathers air will have different intensity and contains impurities such like rainfalls snow and sands It can cause more absorption reflection and diffraction to influence the network performance on Average of Response Time ART and Packet Loss Rate PLR In Hidayab s also 12 shows two figures of signal strength under windy environment and ideal environment The difference is minor but the author 30 believes that the outdoor environment such as wind and drizzling also caused the path loss during propagation Especially in a forest environment rainfall will cover on foliage From RF point of view the density of the transmitting medium is changed It causes more attenuation on the signal propagation path In the area of FOP the main weather situation in winter is rainfall and fog The Weissberger s model does not include the factor caused by humility Therefore in the FOPW design we need to consider the influence of foggy and raining weathers 3 3 6 Solar Power The key issue of building a self sufficient system is the power resource Typically there are several ways of drawing power from the nature such like solar power wind force and waterpower Solar power is the most common and efficient resource to be used in a mountain
10. sunset dawn and dusk times for the whole year The daytime duration of FOP is from 10 hours to 15 hours due to different season However the MPP is assumed to achieve during the peak hours When the output current is bigger than 80 of the maximum value we assume the sunlight is in peak hours By knowing that we can choose the proper size of the solar panel for both Nodes Table 3 shows output values of different sizes of solar panel More power will charge batteries faster keeping them topped up for cloudy days Too little power may cause a power outage from drained batteries due to decreased charge capacity Table 3 Solar Panel Power Output Rate Rated Rated Open Circuit Dimensions Panel Power Voltage Current Voltage H w d in inches Weight 40w 12V 2 41A 22 2V 50 9 13 1 4 22lbs 50w 12V 3 15A 19 8V 48 0 13 0 1 3 171lbs 70w 12V 4 25A 21 4V 47 3 20 8 2 2 23lbs 100w 12V 6 00A 21 0V 56 9 20 8 2 2 26lbs 32 Once the sunlight is converted into electricity a controller controls the working state of the entire solar power system to protect the batteries from over being over charged When the modules generate enough power for the loads the extra power can be stored in batteries for use in the nighttime and any weather conditions without sunlight Lead acid batteries are commonly used for the solar power systems P fo Q amp XO O DO Darkness MDS Sunshine DUSK Figure 10 Sunrise
11. the rainfalls paste on trees and the leaves for sometimes that can attenuate the RF signal Water absorbs and reflects the RF signal and the penetrability of RF signal decreases Antenna height is another factor to influence the signal strength Increasing the antenna height can improve the signal reception and coverage Antenna directionality has a small influence on the signal penetrability in forest environments because of high density of trees and inter twisting of branches and leaves The total cost of the FOPW design is 2170 17 including the three nodes and two solar power systems See Appendix B The costs of the installation such as the tripod and the installation kits are unexpected Referring to Figure 18 the original design requires digging a 3 feet deep hole in the ground and inserting the mounting pole in it 58 However this structure is not stable to stand Therefore we need to purchase a stronger tripod to hold the mounting pole In that case the total cost of ROPW design would be over the budget See Appendix A From Figure 28 the total cost of the three nodes is 1340 31 The average cost per node is 446 77 Compare to the two professional solutions mentioned in Table 1 the cost per node of the FOPW design is much lower than theirs Total Cost Miscellaneous 147 8 Figure 28 Total Cost of FOPW Design 59 7 Reference 1 Google Earth free software http www google com earth index html 2
12. to 13 channels spaced 5 MHz apart each channel has a bandwidth of 20MHz 802 11n protocol has same property but has a 40MHz wide channel on 5GHz operating 802 11n can operate on 4 streams because of adding Multiple Input Multiple Output MIMO antennas The MIMO streams have better performance on severing multiple clients The IEEE 802 11n protocol allows a maximum of four MIMO streams and can achieve a 600 Mbit s data rate with four spatial streams using on 40 MHz wide channel Both of 21 802 11g and 802 11n protocols use OFDM Orthogonal Frequency Division Multiplexing spread spectrum system They transmit multiple signals over a single path within its own unique frequency range in order to distribute the data over a large number of carriers The benefit of OFDM modulation method is easily adapted to sever channel conditions and lower multi path distortions It has high spectral efficiency and low sensitivity to time synchronization errors Table 2 802 11 Protocol Comparison 802 11 Freq a Allowable Maximum Modulation protocol GHz MIMO streams Data Rate Mbit s MHz G 2 4 20 1 54 OFDM DSSS 2 4 20 4 72 2 per stream A 5 40 4 150 per stream SEEM 3 3 2 Router Access Point and Repeater Router Router is the core device of a network It forwards data packets between networks and plays the role of gateway In a network router determines the path a data packet shall take Especially a router wi
13. 90 11 Battery 8 14 112 12 AC DC Inverter 1 35 35 13 GPS Sensor 1 25 25 14 USB Wireless Adapter 1 30 30 15 Tri Pod 1 1 275 275 16 Tri Pod 2 1 39 39 17 PVC pipe 2 5 10 18 Coaxial Power Plug 2 1 49 3 97 19 XL Clip Box 2 6 99 15 16 20 Enclosure 2 5 10 21 Installation Kit 3 30 90 22 Pipe Connector 5 2 69 14 66 Total 2170 17 63 Appendix C Nodes Installation amp Configuration C1 Office Node Installation Procedures Put D link DI 624 router and Hawking HSB2 signal booster in a waterproof plastic enclosure 2 Drill two big holes on the top of the enclosure and insert two pipe connectors for wiring antenna cable power cord and Ethernet cable Drill some small holes on the bottom to radiate heat 3 Wrap the enclosure with tinfoil paper to avoid sunlight heating up the devices Seal the two pipe connectors on the top 4 Mount the enclosure and antennas on the top of a steal pole 5 Hold the pole with a tripod 6 Adjust the direction and tilt angel of antenna d Figure 29 Office Node Installation 64 C2 Middle Node Installation Procedures 1 Put a Linksys WRT54G router and two of Hawking HSB2 signal boosters in a waterproof plastic enclosure 2 Drill two big holes on the top and one big hole on the bottom of the enclosure Insert two pipe connectors for wiring antenna cable power cord and Ethernet cable Drill some small holes on the bottom to radiate heat 3
14. Coverage nul Vey ceo ev ee n PN hu Ru ANS eis dei mtf icri t n atiis 76 D7 Received Signal Strength Survey 4 oie epatis eae de eei aae Ane aere e nr ag eee dean T11 Appendix E Data Shee cesio eesi ie a etc E A ead ashes 78 Bile Dr link DIE 624 Roter taber cs opio Loa tees b RESES 78 E2 Linksys 54G BOULE iae et pet adhe haa dae d o ont Reeds 78 E3 Hawking HOW2R1 Smart Repeater s smeesressressrrrsrrreneresrrerrrrrrrrssrrrsrrrrrrr rr rr rr rerna 78 EA Hawking HAO14SPD Panel Antenna eerie eene ener nete 78 E5 HawkingHSB2 Signal BOOSter sssesesssrsssresersrresresersrrssrrssrsrrssrrssrsrrs DER Ue sr rerna 78 E6 USB Wireless Adapter lt 9 2 02asizs scod oscaleiiueceaulavcsisates cp hateensa cunceacioeceitatag ceeds pede 78 E7 Sunforce 50048 Solar Panel Kits 45 oir pota rto ien eiut pci de media 78 E8 Power Bright PW400 12 Power Inverter eese 78 E9 GPS SeN OT cde ese eese um e tiques edite auae id a niea 78 List of Figures Figure Fairfield Osborn Preserve on Google Earth esee 12 Figure 2 Weather Station Settled in Osborn Fairfield Preserve sess I3 Figure 3 Distances between Each Node amp End Node Coverage sss 19 Figure 4 Design Architecture eere reo on ete teer et SUL Rede Deva ies 20 Figure S WLAN Modes edi e eR iiu 21 Figure 6 Panel Antenna Radiation Patterns 10
15. Node Design 4 2 4 Solar Power System Design In order to build a self sufficient system both the Middle Node and the End Node require Solar Power System to generate enough power to use The Solar Power Systems not only generate power to use in daytime but also conserve power in nighttime and days without any sunlight The design has to follow four steps calculate the power requirements choose the right solar panel choose the right batteries and build a rugged structure to support equipment First step is calculating the power requirements After measuring the power consumption of every item we find out the Hawking HSB2 signal boosters and HAO2RI Smart Repeater have fluctuating value for the power consumption due to varying throughput The results are listed in Table 6 The measurement procedures are shown in Appendix D1 D2 and D3 We can predict the power consumptions of the Middle Node and the End Node by adding different components Amp hour represents the number of 41 hours that a 1 amp current drawing device will be powered by a particular battery before it runs out of energy Table 6 Power Consumption for the Router the Signal Booster and the Repeater Load Items Voltage Current Power Average amp hour V A W Day Linksys WRT54G Router 12 0 45 5 4 10 8 Signal Booster 12 0 01 1 2 0 12 14 4 14 52 Smart Repeater with AC 12 0 85 0 91 10 2 10 92 21 12 DC inverter Once we find out
16. RSSIs and export data into kml files 3 Display the kml files on Google Earth shown in Figure 38 Fairfeild Osborn PreservefOffice n Middle Node End Node Figure 37 Coverage Survey Route Figure 38 RSSI from Office Node to End Node 76 D7 Received Signal Strength Survey Survey Procedures 1 Walk to the location of the Middle Node Use InSSIDer to capture RSSI of the SSID named Office Node Observe the minimum value and the maximum value of the RSSIs 2 Walk to the location of the End Node Use InSSIDer to capture RSSI of the SSID named Middle Node Observe the minimum value and the maximum value of the RSSIs 3 Export the capture data into Google Earth Result As shown in Figure 39 the minimum RSSI captured at the Middle Node is 68dBm and maximum value is 78dBm The minimum RSSI captured at the End Node is 68dBm and maximum value is 76dBm Middle Node iere MN Kexe k Figure 39 Middle Node amp End Node RSSI Survey 77 Appendix E Data Sheet El D link DI 624 Router Data Sheet ftp ftp10 dlink com pdfs products DI 624 DI 624 ds pdf E2 Linksys 54G Router Data Sheet http homedownloads cisco com downloads datasheet wrt54 gv8 ds pdf E3 Hawking HOW2R1 Smart Repeater Data Sheet http hawkingtech com index php products downloadfile 36 html E4 Hawking HAO14SPD Panel Antenna User s Manual http hawkingtech com index php products downloadfile 134 html
17. Rea euer een e pelo ades 48 Figure 23 The Signal Strength for Different Antenna Heights sss 51 Figure 24 End Node Coverage in Different Antenna Height sss 52 Figure 25 Signal Propagation in Vertical DireCtiONS sseesseessrsssssrersrssersrrssrrsersrrsnrn 52 Figure 26 Signal Propagation in Horizontal Directions sesssesessserssrsrrrsrrssrrrersrrsrrn 53 Figure 27 Network Performance in Different Weather see 54 Figure 28 Total Cost of FOPW Design rustic erect etre secador eda tdeo teen eda 59 Figure 29 Office Node Installalloli 5293 recte esed eee vitem OU ee INL 64 Figure 30 Middle Node Installation iioii a eei eet Ced pe Fede eode 66 Figure 31 Linksys WRT54G Configuration esses nennen nennen 66 Figure 32 End Node InstallatiOn sssesssrssesserssresersrresressrsrrssrrssrssrssrrssrsr rr sr rs btae dates 68 Figure 33 RSSI vs Distance Antenna Height is 3 feet 73 Figure 34 RSSI vs Distance Antenna Height is 6 feet 73 Figure 35 Signal Strength from Office Node to Middle Node in Sunny Weather 74 Figure 36 Signal Strength from Office Node to Middle Node in Foggy Weather 75 Figure 37 Coyerave Survey BOUE eaae adu iii seus dede ape eee o aao Gun I Sab ed Eu iUnd 76 Figure 38 RSSI from Office Node to End Node te eger rie gehe 76 Figure 39 Middle Node amp End Node RSSI Survey
18. Set the angle between the transmission path and ground of Office Node transmitter antenna to 30 Keep the horizontal angle at 0 The weather is sunny 2 Walk from Office Node to End Node and record RSSIs along the path 3 Walk to End Node connect laptop to End Node wireless 4 Use WinPing to ping Office Node by IP address of 192 168 2 1 5 Repeat step 1 to step 4 in foggy weather Result 1 Figure 35 shows the RSSI captured on the path from the Office Node to the Middle Node when it is sunny Sop PS RI73 USB weiss LAN Card Packet Schedder Mripat MAC Adde 40 ASSI Ohannet Vendor Pio Maw flate Nemak Type Fist Seen ETT D Lisk Cupa Nore 4 fvaatuete Aun BELT T MO 12258 A TIT LI LANs FS On Location Logging to office 4 15 9p 83 7548 i Wireless Network Co Figure 35 Signal Strength from Office Node to Middle Node in Sunny Weather 74 2 Figure 36 shows the RSSI captured on the path from the Office Node to the Middle Node when it is foggy weather B esspe 2 0 2123 USB Wireless LAN Card Pahat Schedules Viripo Owrnei Vendor Pwacy Max Fiske Meach Tepe Far Sem LanSeen Laude Longitude 4 1 ANS Gps Or Lacaoon Logging ta dice 4 15 gue 162 MEE Figure 36 Signal Strength from Office Node to Middle Node in Foggy Weather 75 D6 Coverage Survey Survey Procedures 1 Holding a laptop installed InSSIDer walk along the red lines shown in Figure 37 2 Record
19. The last section summarizes five fundamental theories to help understanding the challenges of designing a WLAN in a forest environment 3 1 Design Challenges The goal of the purposed FOPW design is to create a self sufficient outdoor WLAN and evaluate the network performance in different weathers In order to achieve the goal there are two critical challenges to resolve the power consumption and the coverage Coverage The FOPW extends Wi Fi coverage from the FOP office building to the area around Turtle Pond There is a hill on the radio wave propagation path Therefore an intermediate node sets up on the top of the hill to pass the signal from the office building 17 to the End Node Then the End Node rebroadcast the signal to cover the area around the Turtle Pond Shown as Figure 3 the total distance from the office building of FOP to the End Node is 371m There are many trees grown on the hill that are over 20 meters high and also it is impossible to put antennas over the height Therefore there is no line of sight LOS between the adjacent nodes The signal attenuation multipath fading and various interferences caused by trees all become issues to affect communications between the nodes When the connections become unreliable packets are dropped during transmission which means the data captured by the weather stations will be lost Increasing the total system gain and the antenna height and avoiding the obstacles can help trans
20. Wrap the enclosure with tinfoil paper to avoid sunlight heating up Middle Node Seal three pipe connectors Mount the enclosure and two Hawking HAO14SPD Panel Antennas on the top of a steal pole 4 Adjust the directions of both antennas Make sure one antenna point to Office Node another one point to End Node 4 Put 25 pounds cement in a basket to act as a basement Insert the steal pole into the basement and use a tripod to make it solid 5 Put solar panels on the ground Adjust the direction to south and tile angel to corresponding seasons 6 Connect solar panels batteries and electronics devices with a smart controller Configurations 1 Open browser to http 192 168 1 1 Change Wireless Mode to Repeater Bridge Change Wireless Network Name SSID to Office Node 2 In Wireless Advanced Setting page set TX Power to 65 In Radio Time Restrictions we can schedule to shown down the radio in a daily routine For example shows the radio will shut down from Oam to 5am and from 20 pm to 24pm every day 65 dant Wireless Basic Settings Radius Wireless Security Wireless Physical Interface wl0 MAC Filter Advanced Settings Physical Interface wl0 SSID Office Node HWAddr 00 18 39 FD A7 8C Wireless Mode Wireless Network Mode Wireless Network Name SSID Wireless Channel Wireless SSID Broadcast Sensitivity Range ACK Timing Network Configuration Virtual Interfaces Repeater Brid
21. design is introduced in section 4 2 4 The installation procedures are provided in Appendix C2 4 2 3 End Node Design Figure 16 shows the components of the End Node The End Node picks up the signal sending from the Middle Node and rebroadcasts it to cover the area around the Turtle Pond The communication unit is a Hawking HOW2RI Outdoor Smart Repeater See Appendix E3 The repeater has an internal directional antenna to communicate with the Middle Node and two external Omni directional antennas to create Wi Fi coverage Same as the Middle Node the End Node requires a solar power system as discussed in the next sub section The smart repeater uses Power Over Ethernet POE technology to pass electrical power safely along with data over Ethernet cabling 12V DC power supply cannot power up POE devices Therefore the End Node uses a DC AC inverter to transform 12 DC power into 220V AC power for use by the smart repeater The installation procedure is of End Node is shown in Appendix C3 40 Repeater Solar Panels POE TNC Port TNC Omin es Omin g Directional a Directional Antenna oO Antenna e 2 B e POE pon Lan Smart Controller Port POE Injector J E AC DC Adapter ne x DC AC Inverter Batteries Figure 16 The End
22. is a negative number in dBm Therefore the path loss is the subtraction of the Receiver RSSI and the total system gain The measured path loss of the first link is from 123dB to 133dB The second link has a measured path loss in the range of 121dB to 129dB Both of the theoretical path losses are in the corresponding ranges The results show that the 49 Weissberger s Modified Exponential Decay Model is applicable to predict the signal path loss in an environment with much foliage Table 9 The Path Loss Comparison over The Links Link TX RX TX Total RSSI Measured Theoretical Antenna Antenna Power System Gain dB Path Loss Path Loss Gain dBi Gain dBi dBm dB dB dB Office Node 68 123 to 14 14 27 55 to to 125 Middle node 78 133 Middle Node 68 121 to 14 12 27 53 to to 120 End Node 76 129 5 2 The Network Performance Test According to Table 9 the total system gain is the subtotal of the transmit antenna gain the receive antenna gain and the transmit power which is 55dBm for the link between the Office and the Middle Nodes and 53 dBm for the link between the Middle and the End Node However the FOPW system has to deal with an extra huge attenuation which is about 0 2dBm 0 5dBm meter caused by forest environment The signal would drop to an unreliable level in 200 meters It is very important to optimize the received signal strength to insure the connections
23. is about 200 to 300 However indoor APs are not designed for outdoor environment Compared to the outdoor products the indoor products are difficult to keep in stable status beyond room temperature Besides that the indoor products usually have lower transmit power than the outdoor products which will give the indoor devices shorter signal range Typically an indoor router has a 300 metersignal range if there is no obstacle on the signal propagation path Other than the mentioned DIY projects Meraki 4 and Trango 5 are two companies that manufacture high performance outdoor devices and offer professional solutions for outdoor WLAN design Their expertise is to design and implement a reliable WLAN with high performance Meraki uses four high performance outdoor APs to establish a roughly pentagonal shaped wireless mesh network with over 500 meter across straight through the heart of the Jefferson National Forest in University of Virginia Each AP costs more than 2000 Trango System provides another outdoor solution Because 900MHz system offers excellent receiver sensitivity and penetrability in a forest environment their subscriber unit can expect no line of sight NLOS performance of up to 6 miles or beyond Each node costs over 13000n average The advantage of the professional solutions is all the devices having high performance in areas with different weather and they are easy to operate However the cost is unaffordable It costs easi
24. light in vacuum f Signal frequency in MHz d Distance from the transmitter in meters Equation 1 Free Space Path Loss 8 From Equation 1 we know a fact the longer the transmit distance and the higher the operation frequency the bigger would be the attenuation The second phenomenon is the reflection which occurs when the radio wave is transmitting in different mediums Reflection is caused by impedance mismatch so it is often measured in a dimensionless ratio know as Voltage Standing Wave Ratio VSWR In an outdoor environment reflection would occur of buildings surface of earth or plants The reflected waves follow the typical laws of reflection The incident angle is equal to the angle of reflection and that the wave undergoes a phase change of 180 degrees The third phenomenon is absorption When the signal wave is transmitted through a medium a portion of its energy will be absorbed Especially in an outdoor environment complicated weather situations and terrains will cause much more absorption than an indoor environment The fourth phenomenon is diffraction Diffraction occurs when the radio is transmitted it obstructed by a sharp edge 9 The radio signal impinging on the edge results in secondary waves that propagate in all directions around the edge including behind the 24 obstacle Diffraction is responsible for providing a path between the transmitter and the receiver even when there is no direct or reflected
25. path The diffraction depends on the geometry of the object as well as on the amplitude phase and polarization of the incident wave at the point of diffraction The last phenomenon is interference In physics interference is the phenomenon in which two waves superpose to form a resultant wave of greater or lower amplitude In a WLAN two Radio Frequency RF signals performs in a nearly frequency will cause a cross talk or attenuation Two waves could be from one source or two different sources All of these phenomena will be considered as a factor to influence WLAN performance 3 3 4 Antenna Principle The antenna is a key building block in the construction of wireless communications systems The purpose of this sub section is to provide an overview of fundamental antenna properties and performance characteristics There are four concepts included passivity radiation patterns beamwidth and Fresnel Zone This knowledge can be used to establish antenna selection criteria for optimum system performance First antennas are passive devices To operate they require no supply voltage and they do not amplify RF energy Antennae convert electrical energy to RF waves in the case of transmitting antennae or convert RF waves into electrical energy in the case of receiving antenna The physical dimensions especially length of an antenna are directly related to the frequency at which the antenna can propagate or receive waves Total amount of energy em
26. the other one is used for backhaul downlink He claims in the beginning of chapter 9 in his book that by using signal booster and high gain antenna the system can be located out as far as the eye can see A solar power system also embedded with his repeater node By collecting energy directly from the Sun with a 70W solar panel the repeater node becomes a standalone system on the top of a hill where there is no AC power resource to access All communication devices and two lead acid batteries are put in an 18 18 6 inch waterproof steel box Even though the repeater node has an outstanding performance it is very heavy to carry on up a hill and attach to a steel pole Denny Mavromatis 3 did another DIY project that modified a Linksys router to work as a bridge He puts the router in a waterproof enclosure with an 8dBi Omni directional antenna So that he was able to pass the Wi Fi signal from his parents house 200 meters away He did not have a solar power system to power up his system but used AC power from his house Due to the limitation of hardware the modified repeater did not work reliably He says he had to reboot the repeater once a while and lost connection in rainy days One common problem 14 in these projects is the modifying indoor routers to work as outdoor APs or repeaters The reason for modifying the indoor products instead of buying outdoor products is to reduce cost Without solar power system the average cost of each node
27. the power consumptions of the Middle Node and the End Node the solar panel sizing becomes the second step In the FOPW design we choose Sunforce 50048 12V 60W solar panel sets See Appendix E7 The set includes four 15W solar modules The following sizing processes determine how many solar modules are required for the Middle Node and the End Node Middle Node 1 Total average amp hours per day for The Middle Node 25 32 2 Average sun hours per day in the position of Middle Node 5 3 Divide line by line 2 for total solar array amps required 5 064 4 Divide line 3 by 0 85 to compensate for the solar panel efficiency 5 96 5 Peak Amps of solar module used 1 6 Total number of solar modules in parallel Divide line 4 by 5 5 96 End Node 1 Total average amp hours per day for The Middle Node 20 64 2 Average sun hours per day in the position of Middle Node 6 3 Divide line 1 by line 2 for total solar array amps required 3 46 4 Divide line 3 by 0 85 to compensate for the solar panel efficiency 4 07 42 5 Peak Amps of solar module used 1 6 Total number of solar modules in parallel Divide line 4 by 5 4 07 The power generated by the solar power modules should be bigger than the power used by the nodes Therefore the numbers of modules required to provide enough power per day is 6 for the Middle Node and 5 for the End Node The third step is to choose the right batteries The capacity of the batter
28. which caused by trees and other vegetations The FOPW design offers the Internet access under its coverage We have been successful to check our emails and load YouTube videos within the coverage areas By increasing the height of antennas the FOPW design can cover the major area around the Turtle Pond 37 By measuring the path loss between each link we know that the Weissberger s model is accurate enough to account for the signal loss However the Weissberger s model does not include any factor for the weather impacts We can only predict the path loss when the signal propagation path is blocked by dense dry and leafy trees When the entire system is completely installed and configured the performance test shows the weather has a great impact on the signal propagation By evaluating the performance of the FOPW design we know that the weather significantly affects the propagation of the radio signals in the forest environment The Wi Fi signal is not stable in foggy weather in terms of ART and PLR increasing The whole network cannot function during a rainy weather From the study we know that the 2 4GHz radio wave is badly attenuated in the forest environments The penetrability is very poor even when high gain directional antenna with high transmitting power is used Trees cause a lot of reflection absorption and multi path fading Moreover poor weather condition can significantly influence the signal attenuation When it is foggy or rainy
29. 12 Middle Node amp End Node Power Consumption eene 55 Table 3 Detailed Budget x2ousp itinere nou seh adieu l ues apu etes dup fat Edd 62 Table T4 BilboE Mater als ass dto ese n idt utem sopa UE eee ddp pex Lut dev aui 63 Table 15 Linksys WRT54G Router Power Consumption eee 69 Table 16 Smart Repeater Power Consumption Measurement eee 71 Table 17 Middle Node and End Node Power Consumption Measurement T2 List of Abbreviations AP Access Points ART Average of Response Time dBi states the gain of an antenna in decibel as referenced to an isotropic source DHCP Dynamic Hosting Configuring Protocol DIY Do It Yourself EIRP Effective Isotropic Radiated Power FCC Federal Communication Committee FSPL Free Space Path Loss FOP Fairfield Osborn Preserve FOPW Fairfield Osborn Preserve WLAN GPS Global Positioning System LOS Line of Sight MIMO Multiple in amp Multiple Out MPP Maximum Power Point OFDM Orthogonal frequency division multiplexing PLR Packet Lost Rate POE Power Over Ethernet RF Radio Frequency RSSI Receive Signal Strength Indication SSID Service Set Identifier SSU Sonoma State University VSWR Voltage Standing Wave Ratio WDS Wireless Distribution System Wi Fi Wireless Fidelity WLAN Wireless Local Area Network 10 1 Introduction Since last century Earth s average surface temper
30. Fairfield Osborn Preserve Outdoor Autonomous Wireless Network Design and Implementation Final Project Report Sen Guan Submitted to Dr Farid Farahmand and the Senior Design Project Faculty of the Engineering Science Department of Sonoma State University Submitted in partial fulfillment of the requirements for the Master of Science Degree Aug 15 2012 SEE SONOMA STATE UNIVERSITY Fairfield Osborn Preserver Outdoor Autonomous Wireless Network Design and Implementation for FOP by Sen Guan A thesis project submitted to Sonoma State University In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Computer and Engineering Science Acknowledgement First and foremost I would like to express my deep sense of gratitude to the invaluable contributions of Dr Farid Farahmand my project advisor I feel motivated and encouraged every time I meet him I would not complete this project without his abundant help and invaluable assistance support and guidance Deepest gratitude is also due to the members of the supervisory committee Dr Ali Kujoory and Dr Jack Ou without their assistance this study would not have been successful I also wish to express my gratitude to Mr Shahram Marivani the network analyst and adjunct professor of Engineering Department of SSU who rendered help during the period of my project work My special thanks to Centre of Community Engagement of SSU Without their g
31. Intermediate Node End Node Figure 3 Distances between Each Node amp End Node Coverage 3 2 Design Architecture Shown as Figure 4 the design architecture of the FOPW is divided into three parts the controller node the intermediate node and the end node The Controller Node has a wired Internet access and it is in charge of routing the data The Intermediate Node needs to work as a bridge in order to repeat the signal sending from the Controller Node and extend it to the End Node The End Node provides Wi Fi communications to the sensor nodes and the weather stations within its coverage area 19 Intermediate Node Controller Node Wireless Link 1 Wireless Link 2 Figure 4 Design Architecture 3 3 Fundamental Theories Sub section 3 3 summarizes five fundamental theories in the following paragraphs to help us understand the design process more clearly I start with describing the WLAN characterization Then I describe the three components of a WLAN the Router the Access Point and the Repeater The next is the understanding of the radio wave propagation The third is the antenna principle Then I introduce two environmental impacts on signal attenuation At the end of the sub section I present some knowledge of the solar power system 3 3 1 Wireless LANs and Their Characterizations The Definition of WLAN is a local area network which uses a high frequency radio signal to transmit and receive data
32. Mike Outmesguine Wi Fi Toys Wiley Publishing Inc ISBN 0 7645 5894 3 3 DIY Outdoor Wireless Access Point Signal Repeater http www mavromatic com p 426 4 Meraki Network http www meraki com customers casestudies universities university of virginia 5 Trango System http www trangobroadband com wireless products multipoint broadband access M900S 900mhz aspx 6 Chymitdorzhiev T N Electromagnetic Wave Attenuation for Propagation Through a Forest Belt IGARSS 04 Proceedings 2004 IEEE International 7 Shittu W A Prediction of Received Signal Power and Propagation Path Loss in Open Rural Environments Using Modified Free Space Loss and Hata Models RF and Microwave Conference 2008 IEEE International 8 Free Space Path Loss http en wikipedia org wiki Free space_path_loss 9 Tapan K Sarkar A Survey of Various Propagation Models for Mobile Communications IEEE Antennas and Propagation Magazine Vol 45 No 3 June 2003 10 Shenzhen AiJia Communication http www antennachina net tech asp 11 Fresnel Zone http en wikipedia org wiki Fresnel zone 12 Hidayab M Wi Fi Signal Propagation in 2 4 GHz Microwave Conference IEEE 2009 E ISBN 978 1 4244 2802 1 13 Siyu Li and Hongju Gao Propagation Characteristics of 2 4GHz Wireless Channel in Cornfields Communication Technology ICCT 2011 IEEE 13th International Conference 14 Meng Lee and Ng Study of Propagat
33. N RE nns n 20 3 3 1 Wireless LANs and Their Characterizations seen 20 3 3 2 Router Access Point and Repeater suo tae e ea eie so eid tae cedet rn nen 22 2d Radio Wave Propagation doo Quitar cai e US AE 23 3 3 4 Antenna Prmciple eii d een UV AS VARIA XI Visas cee aE trek sie art 25 3 3 3 Environmental Impaets os eoi e eq Ae S M IUe aO PRU auci ERN SDN A 29 Scu OMS 6 21 0 P OM CEN sessio ienud mated eb ve enema s creme SI 4 Hardware Design amp Implementation of FOPW Design 33 A VMS TUBIS NEN NER 33 42 Design Detalls tcc REY ERES E E RAUS TAN EY anes NONE R S RERO UV 35 42 T OPM CIN Oe Desiri o pt us o ru ditis tni oct iaer 36 2 22 Middle Node Designs 5 edge eh es ue bands Nn ee a a n tt 37 4 2 3 Bnd Node Design rete HRS Ue EVEN sen ess eNsders EUER RUNS are ER Rea TE rn E 40 4 2 4 Solar Power System Desist iii ee eee teret tentare bert es de Po Reeta d ein bas sse lesen 41 4 3 Signal Strength Measurement amp Locations Selection sess 45 5 Experiment Results and Analysis 49 Jil Path LOSS Medsur emehit euo ato tt eru E HERUM a ts p m p tuf OR dU id vs 49 5 2 The Network Performance Test eer n eS PEE SPERO SENSU nr rr Pepe orna 50 5 2 1 Impact of the Antenna Height eed geli ied 50 5 2 2 Impact of Different Antenna Propagation Directions eee 52 5 2 3 Impact of the Weather Cond
34. Sunset Dawn and Dusk Times in FOP 14 4 Hardware Design amp Implementation of FOPW Design This section first introduces hardware design and implementation At end of the section we introduce an approach for the signal strength measurement and how to use the approach to select the installation location for each node 4 High level Design Figure 11 shows the location of the FOPW design in a visual way FOPW uses a point to point repeating infrastructure and contains three nodes which are the Office Node the Middle Node and the End node The Office Node is considered as a controller 33 node that will be set up around the office building of FOP The facility provides the Internet access and AC power The Office Node creates a wireless network and transmits2 4GHz signal through a high gain directional antenna The hill in the area blocks the signal transmission from the Office Node to the End Nodes A Middle Node is introduced at the top of the hill to perform as a bridge to relay the signal from one side of the hill to the other The End Node is located beside the Turtle Pond to create Wi Fi signal coverage around the pond Two solar power systems provide power for the Middle Node and the End Node Middle Node P d x nternet Acces 27 N a d N Pd x Pd N i ax e ae m a Gm ae ojojo Office Station Figure 11 The High Level Data Communication Design Figure 12 shows the
35. ap one can collect the capability to measure the signal coverage with meaningful signal strength over time in the area If there is no GPS sensor configured the values show all zero In Figure 35 these two categories show the real time values of latitude and longitude For example Figure 20 shows the track when people carry a laptop loaded with InSSIDer and travels in the FOP Green bubbles indicate the RSSIs captured by InSSIDer on the travel path The sizes of the bubbles indicate the strength of received signals The biggest bubble location is assumed to be the location of transmitter oo mee BAAA on Bile Edit View Jools Add Help Search Find Businesses Directions Google earth e Figure 20 The Signal Strength Captured by InSSIDer as Shown in Google Earth Map The location of the Middle Node is not only having good signal reception but look as good as an open area for the solar power aspect There are three open areas marked as B1 B2 and B3 shown in Figure 21 that could be used to set up the Middle 47 Fairfeild Osborn Preserve Office 4 i ud End Node Figure 21 Middle Node and End Node potential locations Using the approach introduced earlier this sub section the RSSIs capture at each locations are shown in Figure 22 The reception at B1 is slightly better than the others Figure 22 Middle Node Reception Survey From Table 8 we also observe that B1 has the best communicatio
36. ature has increased more than one degree Fahrenheit and the rate of warming is nearly three times Most of scientists believe global warming becomes the major issue of climate change Global warming generates a series of consequences such as the retreat of glaciers rising sea level desertification and so on It also brings some serious damages to ecosystem and agricultural Especially it has a significant impact to wildlife It even accelerates the extinction of some species However people know very little about the changes between biological diversity and climate Therefore monitoring environment and wildlife becomes a very important object to sciences and researchers As a multidisciplinary university Sonoma State University SSU has been committed to the research of protecting ecological environment and wildlife The SSU Field Stations amp Nature Preserves provide lands facilities databases and programs that inspire participation collaboration and innovation in education and research at their preserves Fairfield Osborn Preserve FOP was one of it that managed by the SSU Field Stations amp Nature Preserves department The 411 acre Osborn Preserve lies on the northwest flank of Sonoma Mountain predominantly in the Russian River watershed at the dry southern end of the North Coast Range of the northern California The Nature Conservancy established Fairfield Osborn Preserve in 1972 through the generosity of William and Joan Roth in honor
37. between each node and improve the network performance In sub section 5 2 we analyzed three experimental results of the signal strength measurement and the networking performance test under different criteria 5 2 1 Impact of the Antenna Height For the wireless sensor networks the antenna height of the transmitter and the receiver should be raised high enough to obtain a clear Fresnel Zone In that case the plant impact on path loss could be negligible However the antenna height is not the single consideration in engineering design and some other issues such as communication 50 quality economical cost and engineering implementation must be considered In the FOPW project due to the complicated terrain it is impossible to make antennas to cover all desired areas Two different antenna heights 3 feet and 6 feet were tested at the End Node One of the impacts of changing antenna height is increasing the receiving signal strength Figure 23 shows the signal strength captured at different distances from the End Node From the figure we observe that the system has higher gain when the height of transmitting antenna is increased The testing procedures are shown in Appendix D5 1 RSSI vs Distance in Different Antenna Heights E ao D In I5 c Distance m Figure 23 The Signal Strength for Different Antenna Heights Another impact of increasing antenna height is increasing network coverage Figure 24 shows th
38. c The power consumption jumps to 24 2W When the Middle Node has a large throughput loading videos We choose the average value to predict the power consumption of the Middle Node which is 14 65W The current of End Node has a slightly difference between staying ideally and working status We just use 10 32W to estimate the power consumption Based on testing the results six modules of solar panels and six 12V 7Amp batteries are capable to offer enough power for the Middle Node operating as a standalone node Also five modules of solar panels and four12V 7A mp batteries are required for the End Node to operate as a standalone node Table 12 Middle Node amp End Node Power Consumption Middle Node End Node Current no traffic 0 425 A 0 86A Current with traffic 0 53A 1 51A 0 89A Solar Panel Voltage 23 60 V 22 78V Battery Voltage fully charged 12 58V 12 96V Power Consumption average 14 65W 10 32W 5 Future Work In section 6 we elaborate on some future work that can be done on FOPW to enhance it based on the purposed design Larger Backbone At beginning of Chapter 1 Figure 1 shows that the areas circled by yellow the lines needed to be covered by wireless signal However the 55 FOPW presented in this project only covers one of areas In the future a larger backbone is needed to cover the whole preserve For that the repeaters that are similar to the Middle Node can be added to the existing n
39. e coverage of the End Node in different antenna heights When the antenna height of the End Node is 3 feet the signal barely covers the pond The receiving signal strength is mostly under 80dB which is unacceptable When the antenna height increases to 6 feet the coverage of the End Node is better near the area around the pond with average signal strength of 70dBm 51 Antenna Height is 3 Feet Antenna Height is 6 Feet Figure 24 End Node Coverage in Different Antenna Height 5 2 2 Impact of Different Antenna Propagation Directions Because of lacking of LOS between each node the signal attenuation is unpredictable in the aspect of propagation direction Based on the data sheet of Hawking HAOI4SDP panel antenna See Appendix E4 the beamwidth of using antenna is 30 degree in both the horizontal and vertical directions The impact of the antenna propagation direction is tested in both the horizontal way and vertical way The angle between the transmission path and ground is taken to be 30 and 60 See Figure 25 The antenna rotation angle is taken 0 and 30 See Figure 26 E Middle Node Office Node H Middle Node Office Node Figure 25 Signal Propagation in Vertical Directions 52 Middle Node Middle Node Middle Node i b o 39 p gt Office Node Office Node Office Node Figure 26 Signal Propagation in Horizontal Directions RSSIs in these differen
40. e in degrees where beam drops by 1 2 3 dB of the strength at the 0 position Horizontal and vertical vectors must be considered when discussing an antenna s beamwidth Typically an Omni directional antenna will have 26 360 beamwidth on horizontal and 7 to 80 on vertical vector A directional antenna will have 30 to 180 on horizontal vector and 6 to 90 on vertical vector As seen in Figure 6 a directional antenna may have multiple lobes The one with highest radiated energy is called the main lobe and the rest is called side lobes When we are talking about beamwidth of a directional antenna it means the beamwidth of the main lobe Figure 7 10 shows the beamwidth of the main lobe for the directional antenna in Figure 6 3dB EE S 3dB Figure 7 Directional Antenna Beamwidth 10 The last important concept is the Fresnel Zone which is the area centered on the visible Line of Sight LOS between the transmitting and receiving antennas Fresnel Zone defines an area around LOS that can introduce the RF signal interference if blocked RF waves travel in a straight line from the transmitter to the receiver without any obstruction However if there are obstacles along the path the radio waves reflecting off those objects may arrive out of phase with the signals that travel directly and reduce the power of the received signals In Figure 8 11 the green line is the visual line of sight between the wireless signal transm
41. ead Acid batteries End Node requires five of the same kind of batteries The last step is to design a rugged structure to support the equipment Figure 18 shows the design structure for the idea installation Solar panels need to be pointed in the direction of the sun to allow the panel to capture the most amount of sunlight In the FOPW design the solar panels have to point to the south because the location is in the northern hemisphere The solar panels are mounted on steel poles with a certain tilt angle In order to achieve MPP the tilt angle between a solar panel unit and the holding pole is different in different seasons 17 The tilt angles between solar panels and holding poles is calculated and summarize in Table 7 and shown in Figure 17 Table 7 Solar Panel Angel Calculation 17 Summary Solar Panel Angle Calculation for FOP SEASON ANGLE TILT CALCULATION Winter Latitude 0 9 29 degrees 38 0 9 29 63 2 Summer Latitude 0 9 23 5 degrees 38 0 9 23 5 10 7 Spring and Fall Latitude 2 5 degrees 38 2 5 35 5 Summer Winter Spring amp Fall EAR Te Face Q a Lang 3 amp ie e a 63 2 Sor p Pole Pole Pole Figure 17 Solar Panel Tilt Angle 44 I lorizontally Polarized M tiny Antenna je U Bolts Vertically Polarizod nteni 3 Meter m 18 U Bolts or 9 8 feet Weatherproof Fnclosure Solar Mounting Bracket Mounlin
42. enerous funding this project would not have been materialized I would also like to acknowledge the work done by Shivam Aditya His thinking and contributions helped me to develop the solar power system of this project Last but not least I wish to avail myself of this opportunity express a sense of gratitude and love to my friends and my beloved parents for their manual support Strength and help and for everything Abstract Global climate change exerts a great influence to environment The costs of unmitigated climate change are potentially enormous The environment impacts also cause harm to wildlife Therefore collecting weather information and monitoring wildlife becomes a major object to many researches and studies Many weather stations and sensors have been set in Fairfield Osborn Preserver FOP However people have to collect data manually The proposed Fairfield Osborn Preserver WLAN FOPW project designs and implements an outdoor autonomous Wireless Local Area Network WLAN located in FOP The FOPW covers certain areas where weather stations and sensors exist By connecting to the FOPW weather stations and sensors are able to upload data automatically The system comprises three types of nodes controller node intermediate node and end node The Controller Node has a wired Internet access and is in charge of data roaming The other two nodes will be set in the field to extend the wireless signal coverage There is no AC power resou
43. etwork When more nodes are added to the FOPW design some problem may arise One problem is the network frame The Office Node is not only going to communicate with one Middle Node but multiple nodes Then the Router used in the Office Node has to be capable of handling multiple communications links Another problem is the network performance Data packets will hop multiple times to arriver the destination This will cause longer delay and more chances of dropping packets Improve Reception In order to improve the signal reception there are three alternative designs that can be used One is to use the 900MHz radio frequency to establish the links between each node instead of the 2 4GHz radio frequency With the 900MHz frequency signal can easily go through the forest and reach 1 mile away in any weather The disadvantage is that the cost of the 900MHz components is higher than that of the 2 4GHz Another potential solution is to add more nodes on the propagation path so that fewer trees would obstruct the link The reliability of each link will be improved However more nodes require more power and higher cost Another solution is to increase the antenna height by hanging it under a balloon for clear LOS Clear Fresnel Zone will make sure that the signal can be sent from the Office Node to the End Node in any weathers Applications Using wireless IP cameras to monitor the wildlife and the environment is a very helpful application The higher transm
44. example load YouTube videos on the laptop Then monitor the change of current Result When signal booster stay ideal it only use very little amount of power the current is 0 01A When signals keep sending through booster it becomes very hard to monitoring the current The maximum reading of captured current is 1 12A The most common reading is from 0 4A to 0 8A 70 D3 Hawking HOW2RI Smart Repeater Power Consumption Measurement Equipment Agilent E3631 Power Supply Hawking HOW2RI Smart Repeater Power Bright PW400 12 Power Inverter HP DV4 Laptop Procedures 1 Use Ethernet cable connect Hawking HOW2R1 Smart Repeater to POE injector 2 Connect POE injector to Power Bright PW400 12 Power Inverter 3 Use Agilent E3631 Power Supply to generate 12V DC power 4 Observe current value on Agilent E 3631 Power Supply 5 Connect Power Bright Pw400 12 Power Inverter to Agilent E3631 Power Supply Observe current value 6 Connect HP DV4 Laptop to Hawking HOW2R1 Smart Repeater wirelessly 7 Load YouTube video on HP DV4 Laptop Observe the change of current value Result Table 16 Smart Repeater Power Consumption Measurement Items Voltage Min Max Average Power W V Current A Current A Current A Power Inverter 12V 0 388 0 389 0 389 4 668 Power Inverter 12V 0 796 0 895 0 853 10 236 Smart Repeater No Traffic Power Inverter 12V 0 901 0 912 0 907 10 884 Smart Repeater Traffic
45. g Pole T Figure 18 The Idea Installation 2 4 3 Signal Strength Measurement amp Locations Selection Stable and strong signal strength ensures a wave link keeping connected and having a good data transmission rate It is the most important factor to influence the network reliability and performance By measuring the signal strength in the area with many trees we can find a location for the Middle Node to have the best reception In the FOPW design we introduce one approach to estimate signal strength by using the free Wi Fi network scanner software called InSSIDer 18 Service Set Identifier SSID refers to as a network name or identifier All devices attempting to connect to a specific WLAN must use the same SSID By monitoring and analyzing the signals captured by the wireless Network Interface Controlled NIC card of any computer InSSIDer can inspect the surrounding SSIDs and track the received signals strength in dBm over time The software detected eleven SSIDs as shown in Figure 19 The signals are received with 45 different strength from 37dBm to 79dBm and shown under RSSI category RSSI stands for Received Signal Strength Indication which is an indication of the power level being received by the antenna In addition InSSIDer shows all the detected networks are working under different frequency range and channels In the FOPW design we can use a laptop installed InSSIDer to simulate the RSSIs of the Middle Node Fir
46. ge Mixed 7 Office Node Auto v 9 Enable 2000 2 Unbridged Disable Default 2000 meters Bridged Wireless Network Mode If you wish to exclude Wireless G clients choose B Only mode If you would like to disable wireless access choose Disable Note when changing wireless mode some advanced parameters are succeptible to be modified Afterburner Basic Rate or Frame Burst Sensitivity Range Adjusts the ack timing 0 disables ack timing completely for broadcom firmwares On Atheros based firmwares it will turn into auto ack timing mode Apply Settings Cancel Changes Figure 31 Linksys WRT54G Configuration 66 Modification Procedures 1 Download vxworkskiller Gv8 v3 bin and dd wrt v24 micro generic bin Install TFTP 2 Configure computer s local Ethernet IP address to 192 168 1 100 subnet 255 255 255 0 and gateway 192 16 1 1 3 Power cycle Linksys router 4 Open browser to http 192 168 1 1 5 Use the firmware upgrade dialog to flash vxworkskiller Gv8 v3 bin 6 Wait five minutes and power cycle the router 7 Flash the DD WRT firmware using TFTP Enter command line tftp i 192 168 1 1 8 Upgrade firmware of using wrt 24v micro generic bin 67 C3 End Node Installation Procedures Installation Procedures 1 Mount Hawking HOW2R1 Smart Repeater on top of a PVC pipe 2 Adjust the direction of the repeater to point to M
47. huge loss in the signal strength In a wired network signal will be transmitted through cables We can simply predict the signal loss by the length of the cable However it is more complicated to measure the attenuation of outdoor wireless links especially in a forest environment Many researchers have studied the effect of obstructions on the signal attenuation Hidayab in his paper Wi Hi Signal Propagation in 2 4 GHz 12 claims that the environmental circumstance is an important thing that needs to be taken into consideration He shows that the propagations between an indoor environment with no obstruction and an outdoor environment which has obstruction along the propagation path are quite different The path loss of outdoor scenario is much bigger than the indoor scenario Additionally vegetations cause multiple path fading and interference that will cause more attenuation In order to obtain a clear First Fresnel Zone both the transmitter and the receiver antennas can be erected to high enough location above the obstructions so that the path loss would be negligible When radio wave travels in a straight line from the transmitter to the receiver without any obstacle we can simply calculate the signal strength loss by using Equation 1 However the antenna height is not the only consideration in engineering design and some fundamental principle must be considered such as communication quality economical cost and engineering implementation etc
48. iddle Node 3 Similar as Middle Node a basket with cement is using as a basement to hold the repeater 4 Use an Ethernet cable to connect the repeater to a POE injector Then connect the injector to a DC AC inverter which connect to batteries Connect batteries and solar panel with a smart controller Figure 32 End Node Installation 68 Appendix D Test Plan Procedures amp Results D1 Linksys 54G Router Power Consumption Measurement Equipment Agilent E3631 Power Supply Linksys WRT54G router Procedures 1 Connect Linksys WRT54G Router to Agilent E3631 Power Supply 2 Adjust power from 3 3V to 12V and record current 3 Calculate power consumption by multiplex voltage and corresponding current Result Table 15 Linksys WRT54G Router Power Consumption Voltage V Current Amp Power W 3 3 0 0 3 3 0 76 2 508 5 0 65 3 25 12 0 43 5 4 69 D2 Signal Booster Power Consumption Measurement Equipment Agilent E3631 Power Supply Linksys WRT54G Router Hawking HSB2 Signal Booster HP DV4 Laptop Procedures 1 Connect HSB2 Signal Booster to Linksys WRTS54G router 2 Power up HSB2 Signal Booster by Agilent E3631 Power Supply 3 Adjust power from 3 3V to 12 V In the meantime record current drawing by HSB2 4 Set output power at 12V level Let the router access to the Internet and connect to laptop wirelessly Make a stream go through signal booster For
49. ies decides the expected work duration which means how many hours the system can operate and carry the load without any sunlight In another word the solar power system has to offer enough energy in daytime and save in the batteries so that the system can stay operation and collect data during nighttime until the sunlight comes back Then the batteries can be charged again when the sun returns The Deep Cycle batteries are like any other batteries the less they work the longer they last Therefore a bigger bank not only gives a larger reservoir but also offers longer battery life Powerg ng gt Power 24 h Where Powerg The power conserved in one battery Power The power used by load h Average sunlight peak hours ng The number of batteries Equation 5 Estimation for the Number of Batteries According to Table 6 the power used by the Middle Node 12 66W which is the sum of the power used by the router and the average power used by the signal booster The average power used by the End Node is 10 56W The power conserved in one battery is 84W Based on that numbers of batteries can be estimated by using Equation 5 Middle Node ng gt f9werz G4 7 1266 04 9 gt 4 Powerp 84 End Node ng s FOWefis 24 B 109610453 d Powerp 84 43 In order to protect batteries from over discharge 5096 more batteries need to be added to each node Based on calculation Middle Node requires six of 12V at 7Amp L
50. ion Loss Prediction in Forest Environment Progress in Electromagnetic Research B Vol 17 117 133 2009 15 Sunrise Sunset Dawn and Dusk Time graphic http www gaisma com en location rohnert park california html 16 Average temperature in Rohnert Park http www weather com weather wxclimatology monthly graph 94928 60 17 Panel Tilt Angle Calculation http www solarpoweristhefeature com how to figure correct angle for solar panels shtml 18 InSSIDer http www metageek net products inssider footnote 61 Appendix A Detailed Budget Table 13 Detailed Budget Communication Units Router 50 Bridge 50 Access Point 200 Signal Booster 150 Antenna 300 Enclosure 20 Installation Kits 50 Solar Power System Solar Power Sets 500 Battery 100 AC DC Inverter 30 Testing Item GPS Sensor 30 USB Wireless Adapter 20 Omni Directional Antenna 50 Yagi Antenna 50 Total 1600 Appendix B Bill of Materials Table 14 Bill of Materials Item Description QTY Price Total Hawking HAOI14SPD Signal 1 Booster 3 80 240 2 D link DI 624 Router 1 30 30 3 Linksys WRT54G Router 1 50 50 4 Hawking HOW2R1 Smart Repeater 1 239 239 5 Panel Antenna 3 85 255 6 Omni Directional Antenna 2 30 60 T Yagi Antenna 1 29 95 32 8 8 Basket 2 1 69 3 68 9 Cement 2 20 40 10 Solar Power kits 2 279 95 559
51. ional antenna used has a l4dBi gain with the output of 25mW Implementation process is shown in Appendix Cl Cat5 Cable WAN Lan Lan Lan Lan Port Porti Port2 Port3 Port3 Signal Booster iis em tem m ren SMA extension cable SMA SMA connector extension cable Router Y J Y J Power Power Directional Antenna RP TNC AC DC adapter AC DC adapter AC Power AC Power Figure 13 The Office Node Design 4 2 2 Middle Node Design Figure 14 shows the components of the Middle Node and the solar power system The main purpose of the Middle Node is to establish connection between the Office Node and the End Node The Middle Node contains a Linksys WRT54G router See Appendix E2 two Hawking HAOIASPD antennas and Hawking HSB2 signal boosters See 37 Appendix E5 Same as in the Office Node the antennas are mounted at the top of a 9 feet high steel pole One antenna will point to the Office Node and the other points to the End Node The router and the two signal boosters will be put in a waterproof enclosure under antennas WAN Lan Lan Lan Lan Port Porti Port2 Port3 Port3 Repeater 1 Power Connector Bridge 2 TNC TNC Solar RC Connector Panels V N o Antenna xtension cab
52. ission speed and power consumption requirements would be two challenges for this application In order to 56 monitor the wildlife the remote IP cameras would be hidden in the forest and far away objects Higher resolution requirement of imaging or videos requires higher performance to upload data in real time Due to the environmental impacts the PLR is more than 5 It causes noticeable performance issues such like jitter with VOIP and video streams This application would require more power and in turn bigger solar panels and more budgets Alterative Power Source The climate of FOP is typical Mediterranean regions It is often raining in winter Fog inlands frequently cover along the valley bottoms leaving the upper slopes of the mountain exposed There is not much sunlight in most areas Solar power is quite unreliable in winter Trees also cause a lot of shade blocking the sunlight in daytime Having an alternative power source will help the required power availability for extended time when enough sunlight is not available Wind power could be the best option to combine with the solar power 6 Conclusion After all the proposed FOPW design creates a WLAN network which covers the area around the Turtle Pond and a strip area among the signal transmission path from the Office Node to the End Node By increasing transmit power and using high gain directional antennas the FOPW design overcome the huge attenuation on the propagation path
53. ition ete tette tete t rens rr to sr rr rn ora 53 2 9 Power C onsumplol s host us oq ases tI r ds NG ed ara EESE tU SEESE uA 55 5 F ture Work PM EE 55 6 7 Conclusi m eme a a ee ech SRS O SRA Ea 57 Te Referenc p s a a 60 Appendix A Detailed Budget smmmossssrsrersresnrerrrsrrssrerrrrrrrrrerrsrrrsrrrrrr sr nr sr rr rr rr rr rr rr nr sr rna 62 Appendix B Bill of Materials sse 63 Appendix C Nodes Installation amp Configuration esses 64 OF Office Node issoro oe ento aE a oU euenit beten nen ited aac dete SETER TE 64 C2 Middle NOdE Senang eunian r s t a Sedi eye eo ies 65 C3 End Node Installation Procedures sseseeeeeeeeseesesseeeresressessrerressersresreesreseeseresee 68 Appendix D Test Plan Procedures amp Results sss 69 D1 Linksys 54G Router Power Consumption Measurement sees 69 D2 Signal Booster Power Consumption Measurement serene 70 D3 Hawking HOW2RI Smart Repeater Power Consumption Measurement 71 D4 Middle Node amp End Node Power Consumption Measurement 72 D5 Environmental Impacts nen erase tt eie te dan cas e deres vader Fe oki ert 13 D5 1 Different Antenna Heights vs Signal Strength s sseessesssrerersrsrsrrrsrrrrrrs rt 73 D5 2 Signal Strength vs Different Weathers essere 74 D0
54. itted by antenna does not increase It only distributes the energy around the antenna 25 The second concept is radiation patterns which describes how the antenna directs the radiation energy As stated earlier an antenna cannot radiate more total energy than is delivered to its input terminals Radiation patterns are typically presented in the form of a polar plot for a 360 degree angular pattern in both vertical and horizontal planes Based on pattern ship antennas can be divided into two categories which are Omni directional and directional antennas The Omni directional antennas radiate or receive equally well in all directions They are used when coverage is required in all directions around the horizontal axis and most effective when large coverage areas are needed around a central point Commonly used for point to multipoint designs On the other hand the directional antennas radiate RF energy in one or two directions and are commonly used for a point to point connection Often radiate in a hemispherical or cylindrical coverage pattern They have back and side lobes and if used effectively they may further reduce the need for additional access points Figure 6 10 simply shows the radiation patterns of a typical directional antenna Back Front Side Side Power Power Figure 6 Panel Antenna Radiation Patterns 10 The next concept good to know about antenna is the beamwidth Beamwidth is calculated by measuring the off axis angl
55. itter and receiver The black circle is the boundary of the first Fresnel Zone and indicates the wave line of sight D is the distance between the transmitter and the receiver r is the radius of the first Fresnel Zone at point P d1 and d2 are distances from point P to the transmitter and the receiver respectively 27 Figure 8 Fresnel Zone 11 An accurate calculation of the Fresnel Zone will improve the reliability in the design of a WLAN Equation 2 11 introduces a general way to calculate the Fresnel Zone radius 2 nad dz nU did Where F The nth Fresnel Zone radius in meters d The distance of P from one end in meters d The distance of P from the other end in meters A The wavelength of the transmitted signal in meters Equation 2 Fresnel Zone Determination 11 The first zone n 1 must be kept wildly free without obstructions to avoid radio wave interference Equation 2 11 can be simplified to Equation 3 11 which gives the radius of the First Fresnel Zone by knowing the frequency of operation and total transmitting distance r 8 657 SIT Where r radius in meters D total distance in kilometers f frequency transmitted in gigahertz Equation 3 1st Fresnel Zone Radius 11 28 3 3 5 Environmental Impacts Obstacle vegetation causes the first environmental impact In the FOPW design project the signal has to pass through much vegetation that may cause a
56. le Antenna extension cable Wire V RP SMA RP SMA fe ac Power Signal Signal Power Gom Booster Booster Smart Controller RP SMA RP SMA SMA TNC SMA TNC connect tor connector i JA ae HE p 8 Directional Directional Antenna Antenna Batteries Figure 14 The Middle Node Design The critical design of the Middle Node is to modify an indoor router into a compatible outdoor repeater bridge Table 5 contains the major specifications of a Linksys WRT54G router The hardware design of Linksys WRT54G router brings 4 major benefits to accomplish the modification First the router has a dual attachable antenna design which allows us to switch the original low gain antennas into high gain antennas In additional one antenna can be used to receive RF signal another antenna can be used to retransmit RF single to another direction Second the Linksys router can 38 operate under an outdoor temperature because in the area FOP the average temperature is from 39 0 F 83 0 F 16 in the most time of a year Table 5 Linksys WRT54G Specifications Frequency Band 2 4GHz Data Transfer Rate 54Mbps Transmit Power ImW 251mW Antenna Type Dual attachable Omni antennas Power Consumption 6W Operating Temperature 32 0
57. ly over 4000 on a point to point WLAN design The budget of the FOPW design does not allow us to choose the commercial devices 15 Table 1 The Comparison of Similar Outdoor WLAN Designs Outdoor WLAN Design Frequency Distance LOS Cost Antenna DIY How to create an 2 4GHz Upto Yes 800 16dBi outdoor wireless 3 200m With Solar Grid repeater 2 Power System Antenna DIY Outdoor Wireless 2 4GHz 200m Yes 200 Node 8dBi Access Point Signal Omni Repeater 3 Antenna Meraki University of 2 4 5GHz 152m No 2096 Tax 11 14dB Virginia 4 Node Sector Antenna Trango System 900 900MHz 9656m No AP 10dB MHz wireless radio or 19934Tax Panel NLOS Broadband beyond Subscribe unit Antenna Wireless Network 5 713 Tax The FOPW design tries to find a balance between performance and cost Different from other people s projects and professional solutions it has to deal with more complicated environmental impacts than DIY projects and to have a lower cost than commercial solutions As we know the signal will attenuate very quickly when there are obstacles between the transmitter and the receiver The attenuation rate is from 0 2dB m to 0 5dB m inside the forest canopy said Chymitdorzhiev T N 6 With big attenuation rate users can lose connection even less than a few meters away from a regular indoor router However there is no way to have a clear wave propagation path because there are to
58. main components of each node The Office Node contains one router one signal booster and a high gain directional antenna The router connects to a wired network by Ethernet cable and to create a wireless network As the basic station the router performs DHCP function that creates an IP domain of 192 168 2 The wireless signal is amplified by the signal booster and is transmitted through a high directional antenna The signal booster is set up at the maximum transmit power level to ensure for the signal to reach the Middle Node The Middle Node contains a repeater bridge two signal boosters and two high gain directional antennas The main function of the Middle Node is to receive the radio wave from the Office Node and relay the signal to 34 the End Node The End Node is also a repeater that uses Omni antenna to extend the coverage Two solar power systems are attached to the Middle Node and End Node Office Node Middle Node End Node l Repeater Internet fom Router E Bridge E 5 5 3 Wireless Sensor i o J Signal Signal Signal Access Booster Booster Booster Point DEUS Client o I5 o Bl Cable Wireless AP Directional Directional Directional Antenna Antenna Antenna 3 Wire Wire Wire
59. mitters to send stable signals over the path In addition The End Node has to cover an area of 37370m 185m 202m Sensors and weather stations are set up in the covered area However the sensors and weather stations usually have a low transmitting power Even if they have a good reception their signals cannot reach the End Node In order to obtain an appropriate communications the End Node of the FOPW cannot use high transmit power however we can increase antenna height to extend the coverage Power Consumption For a standalone system a solar power system is required to provide enough power to run the system continuously There are two major challenges for to build a solar power system The first one is to find a shade free area in forest to set up the solar panels The place should satisfy both the solar power and signal strength requirements The solar panel should be put in an open area to absorb enough sunlight during daytime In the meantime the node should receive strong signals at the same place Another challenge is the solar panel output Each node would use several hundreds of watt seconds per day That will require large enough solar panel within affordable 18 price The panel output will vary based on factors such as the temperature panel tilt angle atmospheric conditions and how clean is the path We can adjust the panel tilt angle to improve the output of each solar panel Fainfeild Osborn uy Office m d a
60. n link with the End Node Even though B1 is not the best locations on solar power aspect B1 should 48 offer enough energy to run the Middle Node Therefore Bl is the best location to set up the Middle Node Table 8 Middle Node Locations Comparison Locations RSSIs Received RSSIs Received by Percentage of Peak from Office Node End Node Sunlight Hours Bl 68dBm 76dBm 68dBm 76dBm 50 B2 73dBm 74dBm No Connection 40 B3 74dBm 76dBm 73dBm 80dBm 7090 5 Experiment Results and Analysis This section includes three parts In the first sub section we compare the theoretical path loss with the realistic path loss of both links Then we listed and analyzed three results for the network performance test The last sub section is the results of the power consumption measurement of the Middle Node and the End Node 5 1 Path Loss Measurement Table 9 contains the path losses of the two wireless links in the FOPW design One link is between the Office Node and the Middle Node another one is between the Middle and the End Nodes The path length of each link is 203m and 171m By using Equation 1 and Equation 4 the theoretical path loss for the each link is 125dBm and 120dBm In a wireless system the total system gain equals to the sum of transmit power in dBm transmit antenna gain and receive antenna gain Received Signal Strength Indication RSSI is the relative received signal strength usually
61. nnel 183 IP Domain 192 168 2 192 168 2 192 168 2 Transmit Power 500mW 500mW 500mW 200mW 65mW Antenna Type Directional Directional Directional Omni Antenna Gain 14dBi 14dBi I2dBi 5dBi Max Throughput 54Mbps 27Mbps 27Mbps 4 2 Office Node Design Figure 13 shows the detail of the Office Node The Office Node contains a D link DI 624 wireless router See Appendix El a Hawking HAOI4SPD directional antenna Appendix E4 and a Hawking HSB2 signal booster See Appendix E5 The directional antenna is mounted at the top of a steel pole Because the Middle Node has a higher elevation than the Office Node a tripod is used to hold the steel pole with a tilt angle to make sure the antenna can point to the Middle Node The router and the signal booster are put in a waterproof enclosure right under the antenna In order to connect to the Internet an Ethernet cable is plugged into the WAN port of the router As the base station 36 of the infrastructure WLAN the wireless router of the Office Node creates a WLAN and generates the IP domain for IP addresses from 192 168 2 101 to 192 168 2 200 by using DHCP protocol In the U S The maximum Effective Isotropic Radiated Power EIRP of a radio wave is regulated by part 15 of the Federal Communications Commission FCC rule The rule governs the maximum transmitter power of 27dBm when the antenna gain is 15dBi Thus the transmit power of the signal booster is set at 500mw 27dBm max and the direct
62. o many trees in the FOP Therefore the FOPW design has to overcome huge signal attenuation and obtain a stable performance In the meantime the budget of the FOPW design does not allow us to choose professional outdoor wireless products As it was mentioned in the previous paragraph there are some commercial products in the market that can overcome the difficulty of signal attenuation but they can cost over 2 000 for each node In order to reduce cost I needed to build an outdoor access point by modifying some indoor devices and put them in a waterproof enclosure The total cost of 16 each node is much lower than the cost of a commercial outdoor product but with compactable performance Besides keeping balance between performance and cost to locate a position that can satisfy both the solar power availability and the signal strength requirements is another issue In the middle of FOP there is no AC power resource to use and hard to find open areas for solar panels to absorb maximum sun light during daytime because of the shade of trees We need to find out a place for the solar panels to obtain as much solar power as possible In the meantime the location has to avoid as many trees as possible to reduce signal attenuation on the propagation path 3 Design Architecture amp Fundamental Theories This chapter has three sections First section describes the design challenges The second section introduces the network architecture of FOPW
63. of Joan s father Fairfield Osborn The Preserve was donated to SSU in 1997 The Preserve is dedicated to protecting and restoring natural communities and to fostering ecological understanding through education and research Figure 1 shows a snapshot of the FOP map on Google Earth 1 In the figure the green 11 line shows the boundary of the Preserve The blue line shows the areas where are the weather stations are located 2012 Googler Figure 1 Fairfield Osborn Preserve on Google Earth Because of the impact of the Global Warming more and more researches and studies are concentrated in environment monitoring Several weather stations have been set in the preserve They are used to record different parameters of climate such like temperature and humility Electronic sensors are wildly used in these weather stations to accomplish the goal So far as the sensors receive enough power they can capture accurate data continuously under different weather conditions Besides that sensors are capable to save the weather information automatically without any manual operation until researchers walk to the locations of the weather stations and collect those data Figure 2 shows a typical weather station settled in FOP 12 Figure 2 Weather Station Settled in Osborn Fairfield Preserve Even though these weather stations have so many benefits the users of these weather stations still have difficulty on collecting the data They ha
64. ous region Solar panels solar controller and batteries combine to make a stand alone solar power system However solar panels and batteries only provide DC current In some cases the loads need to be powered up by AC power supply so that a DC AC inverter will be required Figure 9 shows a typical solar power system Sunlight S Solar Module or Array Battery Storage AC Loads Figure 9 Typical Solar Power System 3l The solar panel is the most important part of a solar power system and the most expensive part Many pieces of photovoltaic cells assembled to create a solar panel It absorbs the sunlight and converts the energy directly into electricity by the photovoltaic effect There are three main types of solar cells Monocrystallines silicon Multi crystalline and orthin film silicon Crystalline silicon is the most popular and efficient product as it provides an excellent balance of performance and cost The solar power ratings assume operation at a Maximum Power Point MPP which is generally considered impossible to achieve in the real world deployments The solar panel output varies depending on the physical location of the solar power system and the availability of consistent sunlight exposure The expected output power is somewhere in the 80 to 9096 efficiency range during the peak hours of sunlight As we all know the sun light is only available in the daytime Figure 10 15 shows the FOP area s sunrise
65. over a distance of a few hundred feet and over the Ethernet protocol WLAN is used to extend boundaries of the Local Area Network LAN There are two basic modes for the WLAN the Ad hoc and the infrastructure mode The architectures of both modes are shown in Figure 5 Whereas the infrastructure mode has a central device to control the communication the Ad hoc mode does not Ad hoc devices are only able to communicate with another Ad hoc device in their range including an infrastructure device or any other device connected to a wired network 20 Moreover the security level of the ad hoc mode is lower compared to an infrastructure mode network On the other hand the Infrastructure mode requires an access point as a base station to control communications Access point of an infrastructure WLAN supports increased levels of security faster transmission speed and integration with a wired network The FOPW uses the infrastructure mode bc xa T A Sgn B C c Base Station i t n A A a Ad hoc Mode Infrastructure Mode Figure 5 WLAN Modes Another concept of a WLAN is the communication protocol This WLAN combines 802 11g and 802 11n protocols that are created and maintained by the IEEE LAN MAN standards Committee 802 11 family It consists of a series of modulation techniques that use the same basic protocol These two protocols are compared in Table 2 802 11g and 802 11n The IEEE 802 11g protocol divides 2 4000 2 4835 GHz band in
66. rce outside the building of FOP and the intermediate and end nodes are powered by the same solar power system Besides the hardware design this paper also introduces some fundamental theories for the WLAN characterizations radio wave propagation antenna principle environmental impacts of signal attenuation and the solar power system The last part of the paper includes some experimental testing results and analysis Through experimental measurements we demonstrate that the modified indoor network devices can be effective alternatives for the expensive outdoor devices in an outdoor WLAN design By increasing the transmit power and antenna height the FOPW design overcomes the huge path loss due to foliage We also evaluate the performance of FOPW in different weathers Contents List of EISUEQS oer door anda iE aped pe eap d RONDEN BOONE 7 LAist Ob EQUAL IS o Sii a Men Wed pet iie te dM 8 MISE Tabl S in corse etant utultep mius Gesfaqubmteumeraffum tutte Ee cu 9 List of Abbreviations s emsmssssessrsrrssresersrrrsrrrrrenrrsrrrrrerrr sens hae waa Nedudutsas ncaa 10 1 Introducti n onto init reete ens OR ena er ob bn aa PE RUMORS ES ERE SIUS 11 Ze IIo qus T 14 3 Design Architecture amp Fundamental Theories s sesssosssressrsrrrsrsrsrerersrnrrrerrrsrnr nns 17 31 DesremChallc HgeS i uecusoiee tis ts pP IU a ie oho nicae a anui i nep D 17 2 9 Fundamental Theories secie r S SG VINE E E qu acie eon Qd EU
67. st connect a wireless NIC card with 500mw transmit power to the laptop Then connect a 14dBi directional antenna to the wireless NIC card At last walk around in the FOP and raise the antenna to the same height as the Middle Node would be In this case we can use inSSIDer to inspect the surrounding RSSIs to simulate the receptions of each node Therefore we can locate the best place to install the Middle Node 4 MAC Address 00 19 77 25 C2 50 Met aGeck GN PAerohive N WPA2 Per IBOL z Osco Systems WPA2 Erter d 11 04 47 AM GUEST Osco Sauene Open IL TEC NATI AHAGuest Cisco Systems WPA2Peno 5 110447 AM PUBLIC K Caco Systems Open 5 110447AM 1 admin Gece Systems WPA2 Gte 11 04 47 AM osc Caco Systema WPA2 Erter ur cs 1 IBN Caco Systems WPAZ Erter 11 04 47 AM BOM Caco Systema WPA2 Erter 11 0447 AM 180 A Cisco Systems WPA2Erter 11 04 47 AM DEDC ICOA 3 Osco Systems WPA2Erter 5 ur HP 1 Figure 19 The Wireless SSIDs Captured by InSSIDer 18 One important feature of InSSIDer is to associate Wi Fi reception with GPS coordination By using this feature the RSSIs are associated with GPS coordination and 46 are able to be displayed on to Google Earth map It requires a GPS sensor installed on computer to gather the GPS information In Figure 19 there are two categories on the left side which are Latitude and Longitude By recoding the parameters over time and exporting data to Google Earth m
68. t propagation directions were obtained as shown in Table 10 It can be observed that there is no obvious difference in the signal attenuation in both vertical and horizontal directions In the NLOS case as far as the directional antenna keeps in its beamwidth the wireless signal reception does not rely on the directionality In this NLOS scenario wireless signal propagation takes on certain homogeneity because of the high density of trees and inter twisting of foliage Table 10 RSSIs in Different Directions Horizontal Angle 0 30 60 Vertical Angel 30 74dB 81dB 76dB 84dB 74dB 85dB 60 72dB 82dB 73dB 83dB 75dB 86dB 5 2 3 Impact of the Weather Condition In the FOPW project three tests were taken in a sunny day a foggy day and a rainy day The Average of Response Time ART and the Packet Lose Rate PLR were measured WinPing is a software application that allows you to test network performance First use a laptop and connect to the End Node wirelessly Then enter the IP address of the Office Node which is 192 169 2 1 in WinPing The button Options 53 opens the WinPing options Infinite Loop allows running pings in an infinite loop and shows the average However we can stop the loops at 1000 The Auto Save option allows saving all the pinging information in Infinite Loop Mode A Ping Graph allows us easily to view the information for every loop Graph p
69. th wireless function can establish a WLAN and distribute the connection without the need of cable In an infrastructure WLAN a router is required and works as a base station to control signal communications Access Point Similar to a wireless router the main purpose of an AP is to allow the wireless devices to connect to a wireless network AP usually connects to a wired network and can relay data between the wireless and wired devices on the network The difference between the router and AP is that the router directs the way of the packets whereas AP performs as an antenna If a network is geographically too large to be 22 covered by one AP more APs would be required to make a complete wireless infrastructure Repeater In a wireless communications system APs can only transmit the data only in a limited distance before the quality of the signal degrades Repeaters can pick up and amplify the receiving signal to extend the distance over which data can safely travel When located on top of a hill a repeater can greatly enhance the coverage of a wireless network by allowing communications from one side of the hill to another side However a traditional repeater works in its own subnet with its client devices The primary router and repeater work in different IP domains In order to reduce complexity a Repeater Bridge is introduced to WLAN system A repeater bridge repeats a wireless signal from primary AP and has all clients on the same ne
70. twork This feature can greatly benefits the FOPW design The Office Node and the End Node of FOPW are two cooperating APs set in two opposite sides of a hill They must establish a wireless connection because pulling a wire is restricted and not cost effective Middle Node is built up at the top of the hill and performs as a repeater bridge The node ensures the signal sending from Office Node will reach to End Node Moreover all clients connected to the FOPW are in the same IP domain However repeater bridges have a disadvantage The maximum throughput halves after the first retransmission being made because repeater bridges can be considered bridging and accepting wireless clients at the same time 3 3 3 Radio Wave Propagation Without doubt the performance of wireless communication systems depends in a fundamental way on the RF link As a consequence predicting the propagation characteristics between two antennas is one of the most important tasks for the design and 23 installation of wireless communication systems 7 There are five basic phenomena of radio wave propagation The first one is free space path loss FSPL which indicates the loss in signal strength of a radio wave when it is traveling through free space usually air with no obstacles nearby to cause reflection or diffraction The expression of FSPL 8 in terms of dB is 4 2 FSPL dB 10logio af 20log 9 d 20log 9 f 27 55 Where c Speed of
71. ve to spend considerable amount of time on hiking because some of the weather stations are set in the middle of the forest where one needs a lot of time and energy to reach In order to save time the purposed project Fairfield Osborn Preserve WLAN FOPW provides a wireless network to cover the areas between the weather stations and sensors The FOPW offers Wi Fi signal that can be used to upload the data The researchers do not have to come to the Preserve physically but sit in their offices to control the sensors and collect climate information remotely They can save a lot time and energy Besides that it provides other opportunities and feature such as using wireless camera to monitor wild life and having Internet access in the preserve By knowing the motivation of the FOPW project the next section introduces some background information 13 2 Background In section 2 we introduce four similar outdoor WLAN designs Two of them are Do It Yourself DIY projects and the other two require professional solutions Then I will compare them to our proposed FOPW design After the comparison we can find out the uniqueness of the FOPW design In chapter 9 of Wi Fi Toys 2 the author Mike Outmesguine introduced a DIY project to build up an outdoor wireless repeater node by using indoor devices and solar power system He used two wireless access points operating in bridge mode One access point AP is used for broadcasting the signal and

Guan, Sen. 2012.Fairfield Osborn Preserve Outdoor Autonomous

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