User's Manual

Mobile WiMAX Indoor RAS SPI-2210 System Description/Ed.07

MAC ARQ Function

The indoor SPI-2210 carries out the ARQ function of the MAC layer. In packet data exchange,

ARQ transmits SDU from the transmission side to the ARQ block and retransmits the

packet according to the ARQ feedback information received from the reception side to

raise the reliability of data communication.

The indoor SPI-2210 carries out the following function for the service flows applying ARQ:

 Creation and transmission concerned with ARQ operation

 Feedback processing depending on ARQ types

 Block processing (fragmentation/reassemble/retransmission) depending on ARQ types

 ARQ timer/window management

QoS Support Function

The packet traffic exchanged between ACR and indoor SPI-2210 is delivered to the modem

in the indoor SPI-2210. At this time, the indoor SPI-2210 allocates the queue in the modem

to each service flow that QoS type is specified to observe the QoS constraint given for each

QoS class or service flow and performs the strict-priority scheduling according to the priority.

The modem that receives the packet traffic performs the scheduling by using the uplink/downlink

algorithm, such as Proportional Fair (PF) or Round Robin (RR) and transmits the

scheduled allocation information to an MS through DL/UL MAP.

The MS receiving the DL/UL MAP checks the air resources allocated to the MS and

modulates/demodulates the downlink packet or transmits the uplink packet from the

allocated uplink area.

Since the indoor SPI-2210 provides the QoS monitoring function, it can compile statistics

on packets unsatisfying the latency requested from the QoS parameter according to TDD

frames and report the statistics to an operator via the OAM interface.