Home of RF and Wireless Vendors and Resources

One Stop For Your RF and Wireless Need

WiMAX DLMAP vs ULMAP-Difference between DLMAP and ULMAP

This page describes WiMAX DLMAP and ULMAP messages with all the fields. It mentions basic difference between DLMAP and ULMAP in fixed wimax system as per IEEE 802.16 OFDM MAC specifications.


WiMAX frame structure

Figure mentions wimax frame structure as per OFDM specifications. As mentioned wimax frame consists of downlink SF and uplink SF. DLMAP and ULMAP is carried in the downlink SF in the broadcast burst which carries system critical informations. DLMAP carry location information of downlink bursts in the frame and ULMAP carry location information about uplink bursts. It gives this information in units of number of OFDM symbols with respect to start of the frame. The table below mentions all the DLMAP and ULMAP fields with example values. DLMAP consists of DLMAP IE(Information Element) which repeats as per number of downlink bursts i.e. for 4 downlink bursts 4 IEs exist. Similarly ULMAP consists of ULMAP IE which repeats as per number of uplink bursts i.e. for 4 uplink bursts 4 IEs exist.

WiMAX DLMAP

WiMAX DLMAP Field Example Value
Generic MAC Header(6 bytes) 0x00, 0x40, 0x16, 0xff, 0xff, 0x00
DLMAP type( 1 byte-8 bits) 0x02
DCD count (8 bits) 0x01
BS ID (48 bits) 0x00, 0x09, 0x02, 0x00, 0x9f, 0x45
CID(2) (16 bits) 0x00, 0x00
DIUC(2) (4bits) 0xe (Used for scrambler seed value) (END OF MAP)
Preamble(2) (1 bit) 0
Start time (#Burst2) (11 bits) Gives Start time of DL Burst#2. In units of symbol duration, relative to the start of the first symbol of the PHY PDU. 3*Ts + (length of Burst#1)*Ts
CRC 0x00, 0x00, 0x00, 0x00

DL MAP IE ={ CID, DIUC, preamble present, Start time }
This IEs will repeat as per number of downlink bursts as mentioned.

UL MAP IE ={ CID, start time, sub channel index, UIUC, duration } This IEs will repeat as per number of uplink bursts as mentioned.

WiMAX ULMAP

WiMAX ULMAP Field Example Value
Generic header(6 bytes) 0x00, 0x40, 0x1d, 0xff , 0xff, 0x00
UL MAP type(8 bits) 0x03
Uplink channel ID(8 bits) 0x00
UCD count(8 bits) 0x01
Allocation start time-32 bits (in units of PSs) Starting from3*Ts after how many PSs uplink allocation will start For example, (Long Preamble+FCH+DLB#1+silent period+ TTG=>(5.6ms)=>5600 PSs) { 0x00, 0x00, 0x15, 0xE0}
CID(16 bits) 0xFFFF for broadcast case
Start time(11 bits) 0x000
Sub channel Index(5 bits) (10000) no subchannelization
UIUC (4 bits) 0x2
Duration(10 bits) for example 0x008
Midamble rep. interval(8 bits) 0x00
CRC-4 bytes

What is Difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
Bluetooth vs zigbee
Bluetooth vs zigbee
wibro vs mobile wimax
Microcontroller vs microprocessor
FDMA vs TDMA vs CDMA
FDM vs TDM
CDMA vs GSM
OFDM vs OFDMA
wimax vs lte

Links to WiMAX MAC Layer resources

REG REQ and REG RSP
SBC REQ and SBC RSP
DSA REQ and DSA RSP
UCD,UIUC,DCD,DIUC
DLMAP and ULMAP
WiMAX Ranging Procedure
WiMAX Bandwidth Request procedure
WiMAX Network Entry Procedure
WiMAX CID vs SFID
WiMAX FCH header format
WiMAX TLV Format basics
WiMAX Timers
WiMAX Network Interface types
WiMAX QoS Classes

               

RF and Wireless Terminologies


Share this page

Translate this page