IEEE 802 22 Wireless Regional Area Networks WRANs Raj Jain Professor of Computer Science and Engineering Washington University in Saint Louis Saint Louis MO 63130 Jain cse wustl edu Audio Video recordings of this lecture are available at http www cse wustl edu jain cse574 08 Washington University in St Louis CSE574S 13 1 2008 Raj Jain Overview IEEE 802 22 Key Features IEEE 802 22 Superframe Frame Structure IEEE 802 22 Channel Management Configuration Security Power Management Co Existence Beacon Protocol CBP Geolocation Database Washington University in St Louis CSE574S 13 2 2008 Raj Jain IEEE 802 22 Key Features Uses 54 MHz 862 MHz TV Band Designed to share spectrum when TV broadcast is off 17 km to 30 km radius 100 km in good conditions 100 km QPSK 30 km 16 QAM Washington University in St Louis 17 km 64QAM CSE574S 13 3 2008 Raj Jain IEEE 802 22 Key Features Cont 1 5 Mbps Down 384 kbps Up Coverage 50 locations in the fringe areas and 99 9 time 2 bps Hz 12 Mbps in 6 MHz channel 255 users with 40 1 over subscription Washington University in St Louis CSE574S 13 4 2008 Raj Jain Characteristics of Wireless Standards RAN Range Standard 100km MAN 802 22 10km 802 16 LAN 1000m 802 11 PAN 100m 802 15 1M z H z G 11bps H 4 2 G 200 z 8 H 5 Mb 1 7 G 4 ps 5 z 0M 2 H 3 bps M 5 1 10M 2 2 6 bps 8 Spectrum 54 Data Rate Washington University in St Louis CSE574S 13 5 2008 Raj Jain Similarities Between 802 16 and 802 22 Centralized allocation at BS Service classes UGS rtPS nrtPS BE QoS parameters Peak sustained rates max latency jitter OFDMA Slots DS subframe US subframe Bursts DL UL is called DS US SS is called CPE Connections 12 bit connection ID CID Basic Primary management Secondary management connections Ranging request response Contention Ranging BW request MAC subheaders BW request fragmentation grant management packing ARQ feedback fast feedback Washington University in St Louis CSE574S 13 6 2008 Raj Jain IEEE 802 22 Concepts Spectrum sensing Check if TV WRAN signal is present In band Operating TV Channel N and the first adjacent channels N 1 and N 1 Out of band Any TV channel that is not in band Geo location Latitude and longitude Waypoint Any WRAN device whose location is known Used for geolocation Washington University in St Louis CSE574S 13 7 2008 Raj Jain IEEE 802 22 Superframe Structure Superframe Group of 16 frames with a superframe preamble and superframe control header SCH First frame payload is reduced by two symbols to compensate for Superframe preamble and superframe control header Superframe n 1 Superframe n Superframe n 1 160 ms Frame 0 Frame 1 Superframe Frame Superframe Preamble Preamble Control Header Washington University in St Louis CSE574S 13 8 Frame 15 Frame Preamble 2008 Raj Jain IEEE 802 22 Frame Structure Washington University in St Louis CSE574S 13 9 Self Coex Window Ranging BWR UCS Frame Preamble DS MAP FCH DCD US MAP Burst n Burst 2 Burst 1 Burst 2 Burst 2 UCD SCH indicates whether a frame or coexistence beacon follows it It also indicates the position and duration of quiet period for inter frame sensing DS US boundary is adaptive DS bursts are vertical US bursts are horizontal Urgent Co existence situation UCS notification Burst 1 2008 Raj Jain Channel Classifications and Selection Available Not occupied by TV transmitters Disallowed Local regulation Operating Used by this BS Backup In backup list of this BS Candidate For backup Occupied By other WRANs Unclassified Don t know Unavailable Occupied by TV transmitters Washington University in St Louis CSE574S 13 10 2008 Raj Jain IEEE 802 22 Channel Management Channel Termination req resp Announced by BS if incumbent comes back Channel Add req resp to add TV channels to the BS channels Channel Switch req resp Channel Quiet Request resp to perform measurement Channel Occupancy update BS may get the list of incumbents from a database Washington University in St Louis CSE574S 13 11 2008 Raj Jain Measurements Management Bulk measurement request Sent by BS to unicast multicast broadcast address Includes number of repetition and report frequency Measurement response Stop measurement request Location configuration measurement request Washington University in St Louis CSE574S 13 12 2008 Raj Jain Configuration Management SW Upgrade TFTP server TFTP complete message Washington University in St Louis CSE574S 13 13 2008 Raj Jain Security Management Privacy key management req reply reject ack PKM EAP start transfer PKM SA TEK challenge Washington University in St Louis CSE574S 13 14 2008 Raj Jain Power Management 802 22 stations BS or CPE are not allowed to operate on active TV channel N or the adjacent channel N 1 Maximum EIRP is limited when operating on alternate channels N 2 and beyond Washington University in St Louis CSE574S 13 15 2008 Raj Jain IDRP Incumbent Detection Recovery Protocol BS transmits a channel switching req CHS REQ If a CPE misses the CHS REQ it times out if it does not hear from BS CPE then moves to the next backup channel Washington University in St Louis CSE574S 13 16 2008 Raj Jain Co Existence Beacon Protocol CBP For signaling to adjacent and overlapping WRAN cells and for geolocation CBP bursts are transmitted by selected CPEs at the end of US subframe CPEs decode CBP packets from CPEs in cells operating on the same TV channel or adjacent channels 14 types of CBP packets including CPE beacons CPE beacons are transmitted by the CPEs and contain the TV channel backup channel s BS ID CPE ID CBP packets are used for coexistence and Geolocation Washington University in St Louis CSE574S 13 17 2008 Raj Jain Self Coexistence 1 2 3 4 Two or more 802 22 networks in the same space time frequency Spectrum Etiquette Do not hog the channels Interference Free scheduling Do not allocate slots which interfere with neighboring cell s CPEs Dynamic Resource Renting and Offering Less loaded BSs rent spectrum to more loaded BSs Adaptive On Demand Channel Contention AODCC Washington University in St Louis CSE574S 13 18 2008 Raj Jain Dynamic Resource Renting and Offering BS1 BS2 Needs Channel Has Extra Channels Channel Ad BS3 BS3 Has Extra Channels Needs Channel Channel Ad Rent Request Rent Request Res Allocation Ack Res Allocation Ack Needs channels Doesn t Needs channels Collect Req Return Req Collect Resp Ack Return Resp Ack Washington University in St Louis CSE574S 13 19 2008 Raj Jain Dynamic Resource Renting Cont Resource advertisement Time for which the channel is available for rent Rent Request Bid start time end time
View Full Document
Unlocking...