Slide 1

後卓越計畫進度報告楊舜仁老師實驗室2007.06.04

Slide 2

Motivation An MBMS source entity shall provide multiple classes of service

quality for a single MBMS stream due to Device heterogeneity Diversity of subscriber preference Other issues such as change of

available bandwidth Scalable coding technique cab be

adopted for MBMS service delivery. How to properly transmit the layer-encoded MBMS data

through UMTS radio network is much challenging.

Layered Coder

D

D

D

+

+

Layer 1

Layer 2

Layer 3

32kbps

96kbps

64kbps

Slide 3

The proposed DC Scheme

Layer 1 (Base Layer) Data

Layer 3 Data

Layer 2 Data

Region with , and

Region with

Region with and

Service Class 3

Service Class 1

Service Class 2

UE1

UE5

UE4

UE6UE3

UE2

DCH

DCH*2

DCH

R1

R3

R2

UE1

UE2

UE5

UE4

UE6UE3

UE1

UE2

UE5

UE4

UE6UE3 R1

R3

R2

Scheme I Scheme II Our Scheme

Slide 4

The Channel Allocation Policies of our DC Scheme The abuse of the DCH channels would impact the system

performance especially for normal phone calls. In order to allocate the DCH appropriately, the channel

allocation for our DC scheme should be priority-based. Phone calls are assigned to a higher priority than MBMS sessions. Preemption : Reclaim the allocated DCH from an ongoing MBMS session Re-allocation : Distribute the released DCH resources to one or more MBMS

sessions . Four policies to maintain the preemption and re-allocation lists

Random First-Come-First-Serve (FCFS) Service-Class Oriented (SCO) Power-Aware SCO (PAS)

Slide 5

Analytic Model – Region-Independent (SCO) The power consumption of DCH channels is assumed to be insensitive to the r

egions of the DCH users. The overall DCH resources of a NodeB can be modeled based on the channel

viewpoint. Assumptions and notations

3 service classes are provided. Besides the three FACHs, a NodeB

supports c DCH channels.

n )(,

ijm

h )(,i

jh

m/1n/1

n/1 )(/1 im

New call arrival rateNew MBMS session arrival rate in region i

Arrival rate of handoff callsArrival rate of handoff MBMS sessions for class-j devices to region i

Mean call holding time Mean MBMS session holding time in region i

Mean cell residence time Mean region residence time for MBMS sessions in region i

All exponential distributed !!

Slide 6

Analytic Model – Region-Dependent (PAS) The power consumption of DCHs is region-sensitive. Assumptions

Besides those allocated for the three MBMS FACH channels, a NodeB supports total PWt power resources.

The power required of supporting a DCH for a phone call in region i is The power required of supporting a DCH for a MBMS session in region i is

The arrival rate of new calls to region i of a cell

The mean residence time of a phone-call user in region i

)(in

)(/1 in

Slide 7

Comparison of Analytical model and Simulation