CS 578 - WiMAX Frame and QOS questions
& answers
What modulation and coding scheme is used for the FCH in WiMAX? -
answer BPSK modulation with a ½ coding rate.
What are the four key elements contained in the first downlink burst of
a WiMAX frame? - answer DL_MAP, UL_MAP, Downlink Channel
Descriptor (DCD), and Uplink Channel Descriptor (UCD).
In WiMAX, what is the purpose of the Downlink Channel Descriptor
(DCD)? - answer To describe the downlink burst profile, including
modulation and coding combinations for each downlink burst.
What does the Uplink Channel Descriptor (UCD) specify in WiMAX? -
answer It describes the uplink burst profile, including modulation and
coding combinations, and preamble length for each uplink burst.
How are downlink bursts transmitted in WiMAX in order of decreasing
robustness? - answer In order of decreasing robustness, starting with
BPSK and progressing to higher-order modulations like 64-QAM.
, What is the function of contention slots in the uplink subframe of
WiMAX? - answer They allow subscriber stations to send initial ranging
messages and bandwidth request messages to the base station.
What is the purpose of concatenating multiple MAC PDUs in WiMAX? -
answer To improve bandwidth efficiency by reducing overhead in both
downlink and uplink transmissions.
What are the two types of MAC headers in WiMAX? - answer Generic
MAC header (HT=0) and Bandwidth Request header (HT=1).
What are the five types of scheduling services in WiMAX? - answer
Unsolicited Grant Service (UGS), Extended Real-Time Polling Service
(ertPS), Real-Time Polling Service (rtPS), Non-Real-Time Polling Service
(nrtPS), and Best Effort Service.
Which WiMAX scheduling service is suitable for real-time, periodic
fixed-size packets like T1 CBR? - answer Unsolicited Grant Service (UGS).
Which scheduling service in WiMAX is designed for real-time
applications requiring strict delay and variation in delay, such as VOIP? -
answer Extended Real-Time Polling Service (ertPS).
& answers
What modulation and coding scheme is used for the FCH in WiMAX? -
answer BPSK modulation with a ½ coding rate.
What are the four key elements contained in the first downlink burst of
a WiMAX frame? - answer DL_MAP, UL_MAP, Downlink Channel
Descriptor (DCD), and Uplink Channel Descriptor (UCD).
In WiMAX, what is the purpose of the Downlink Channel Descriptor
(DCD)? - answer To describe the downlink burst profile, including
modulation and coding combinations for each downlink burst.
What does the Uplink Channel Descriptor (UCD) specify in WiMAX? -
answer It describes the uplink burst profile, including modulation and
coding combinations, and preamble length for each uplink burst.
How are downlink bursts transmitted in WiMAX in order of decreasing
robustness? - answer In order of decreasing robustness, starting with
BPSK and progressing to higher-order modulations like 64-QAM.
, What is the function of contention slots in the uplink subframe of
WiMAX? - answer They allow subscriber stations to send initial ranging
messages and bandwidth request messages to the base station.
What is the purpose of concatenating multiple MAC PDUs in WiMAX? -
answer To improve bandwidth efficiency by reducing overhead in both
downlink and uplink transmissions.
What are the two types of MAC headers in WiMAX? - answer Generic
MAC header (HT=0) and Bandwidth Request header (HT=1).
What are the five types of scheduling services in WiMAX? - answer
Unsolicited Grant Service (UGS), Extended Real-Time Polling Service
(ertPS), Real-Time Polling Service (rtPS), Non-Real-Time Polling Service
(nrtPS), and Best Effort Service.
Which WiMAX scheduling service is suitable for real-time, periodic
fixed-size packets like T1 CBR? - answer Unsolicited Grant Service (UGS).
Which scheduling service in WiMAX is designed for real-time
applications requiring strict delay and variation in delay, such as VOIP? -
answer Extended Real-Time Polling Service (ertPS).
