Changes between Version 26 and Version 27 of WIMXCOLUM/CUWIMAX

07/11/11 11:38:55 (11 years ago)




    v26 v27  
    66 * !SungHoon Seo (postdoctoral researcher)[[BR]]
    77 * Jan Janak (visiting scholar)[[BR]]
     8 * Marcus Knuepfer (visiting scholar)[[BR]]
    1011== 2. TODOs ==
    11  1. Contact Facilities to mount pole mask and ODU on outdoor site
    12  1. Request permission from Dean's office, facilities, and real-estate committee
     12 1. ~~Contact Facilities to mount pole mask and ODU on outdoor site~~
     13 1. ~~Request permission from Dean's office, facilities, and real-estate committee~~
    1314 1. ~~Preliminary base station testing with Wi-Fi antenna by using signal power attenuator (it should be set with reduced (lowest) TX power 0 dBm)~~ See ''Section 7. Indoor testing'' for more details.
    14  1. Purchase additional necessary items: a pole mask
     15 1. ~~Purchase additional necessary items: a pole mask~~ (not necessary due the new location)
    1516 1. ~~Ethernet activation (1402B) when all equipments are ready via Patrick (CUIT staff)~~ It will be replaced to the other one because the antenna site was changed.
    16  1. Check rack space (smaller size) for IDU and ASN-GW
     17 1. ~~Check rack space (smaller size) for IDU and ASN-GW~~
    7273    - Solved every problems on both BTS and clients
    7374    - Upgraded OMF aggregation manager with the latest version and checked out that wimaxrf works
     75 1. Indoor testing at IRT on Feb 25, 2011
     76    - Succeeded to scan and connect one of our WiMAX clients (Linux OS) to BS
     77 1. Purchase of a server rack cabinet and a PDU (power distribution unit) via Diasy Nguyen (CRF) and Elias Tesfaye (CS Department) on May 19, 2011
     78    - Triplite 12U rack ($444,73)
     79    - APC PDU for remote power ($425.45)
     80 1. Meeting with Donald A. Schlosser (Assistant Vice President of Campus Opers-Custodial Services, Columbia Facilities) on Jun 09, 2011
     81    - Site survey at 16th floor, Mudd building
     82 1. Started to mount and install WiMAX equipment on site on Jun 14, 2011
     83    - Technicians from Facilities and Nathan Schulzrinne (CRF intern) helped us for the deployment, including: Drilling holes on railings, fixing the mask and the antenna, mounting ODU on wall inside the building, and connecting the coaxial cable between antenna and ODU
     84    - Wired opticla fiber and power cables
     85    - Activation of Ethernet by CUIT (Two ports of Giga-bit Ethernet for Internet connection and for PDU management)
     86 1. Finished installation of the WiMAX BS on Jun 23, 2011
     87 1. First singnal measurement survey on Jun 26, 2011
     88 1. Measurement survey to create the coverage map on Jun 30, 2011
    86101== 6. Site survey ==
    87 Becuase of the various reaons, on Dec. 16 2010, we decide to change the outdoor and indoor sites to the southwest corner of Mudd building, 14 fl, rooftop.
    89 === New outdoor site at Mudd 14th floor ===
     102Becuase of the various reaons, on Dec. 16 2010, we decide to change the outdoor and indoor sites to the southwest corner of Mudd building, 16 fl, rooftop.
     104=== New outdoor site at Mudd 16th floor ===
    90105|| a. Wide view || b. front view || c. SW corner || d. side view || e. detail ||
    91106|| [[ThumbImage(site1.JPG, thumb=200)]] || [[ThumbImage(wall3.jpg, thumb=200)]] || [[ThumbImage(wall4.jpg, thumb=200)]] || [[ThumbImage(wall1.jpg, thumb=200)]] || [[ThumbImage(wall2.jpg, thumb=200)]] ||
    175190       - Note: The file of /var/lib/wimax/WiMAX_DB.bin is changed whenever performing 'wimaxcu scan'
     192== 9. Signal quality measurements ==
     193After deploying the BS on site, we will need to measure the signal quality such as Received Signal Strength Indication (RSSI) and Carrier to Interference plus Noise Ratio (CINR).
     194The measured signal quality information may help to configure the transmission power of the radio signal from antenna at the BS to control the coverage area and the propagation range of the WiMAX system.
     196=== Measurement tools  ===
     197We use the signal measurement application ''wimax_gps_oml2'' for WiMAX which can be found in the following site: []
     198This tool utilizes signal quality measurement according to the location which is gathered by GPS receiver (GlobalSat BU-383, connected via USB).
     200=== First measurement survey ===
     201 1. Measurement procedure
     202    - Set the transmission power of the antenna (''bs_tx_power'') to 30dBm
     203    - Defined 30 locations at Columbia Campus
     204    - Mesured WiMAX signal strehgth parameters (RSSI, CINR, Client Transmission Power)
     205    - Recorded WiMAX radio link parameters with corresponding GPS coordinates on the WiMAX client
     206 1. Results
     207    - A wide outdoor area of the campus is exposed to the WiMAX signal so that WiMAX clients are capable to get Internet connectivity via WiMAX base station
     208    - Areas behind buildings and near the edge of the campus are bad covered, or rather not covered
     209    - The results of the RSSI and CINR measurement are shown in the following figures (drawn through ):
     211|| a. Measured RSSI || b. Measured CINR ||
     212|| [[ThumbImage(0626_mexp1_30dBm.png, thumb=450)]] || [[ThumbImage(0626_mexp1_30dBm_cinr.png, thumb=450)]] ||
     214    - Identified two major problems with the recording through ''wimax_gps_oml2'':
     215       i. The recorded GPS data are inaccurate.
     216          Caused by the urban area with a lot of high buildings the number of reachable GPS satellites alternates between two and ten and consequently the accuracy the calculated GPS position is low and the calculated position alternates between locations that are several hundred feet apart.
     217       ii. The recorded RSSI is not synchronized with the calculated GPS position.
     218       We identified that the GPS position is recorded delayed in comparison to the RSSI. The longer the measurement survey the more delayed is the recorded GPS position. Due this delay the recorded data are not meaningful.
     220=== Measurement survey to create a coverage map ===
     221 1. Measurement procedure
     222    - We solved the synchronization problem of GPS and RSSI data
     223    - We could not solve the accurancy problem. We tried to use an other GPS receiver (HOLUX GR-213 instead of  GlobalSat BU-383) but the results were worst.
     224    - Consequently, we decided to select 128 locations on the campus to create the coverage map
     225    - Additionally, we increased the transmission power of the WiMAX BS to 40dBm (max. ODU) to cover a wider area of the campus
     226 1. Results
     228|| a. Coverage map of measured RSSI || b. Coverage map of measured CINR ||
     229|| [[ThumbImage(063011_mexp2_40dBm_map_rssi.png, thumb=450)]] || [[ThumbImage(063011_mexp2_40dBm_map_cinr.png, thumb=450)]] ||
    178233Last updated on [[Timestamp]]