Background Review 18 DBA scheme IPACT IPACT example
Slide 19
Background Review 19 Transmission window size to notify how
many data that ONU can send to OLT in a cycle Max Transmission
window size : W [i] MAX how the OLT should determine the granted
window size if the requested window size W [i]
Predictive Credit Mechanism 32 Note (1)predictive credit based
DBA mechanism is suitable for the traffic which has smaller packet
size and stable arrival rate but delay sensitive. (2) In the
non-credit DBA mechanism R i is always >=0 and B i =R i
Slide 33
33 WIMAX-Side
Slide 34
Background Review 34 Architecture BS->SS data transmit
mechanism : Broadcast SS->BS data transmit mechanism : TDD
Slide 35
Background Review 35 TDD frame structure divide in two part
(1)downlink subframe (2)uplink subframe
Modified leaky bucket algorithm 39 Modified leaky bucket
algorithm 1. under WIMAX network deal with packet fragmentation is
too complicated so this mechanism is use to solve problem that when
we decide not to do the packet fragmentation 2. let data transmit
in different cycle time
Slide 40
Background Review 40 DBA scheme Grant Per Connection Grant per
SS Schedule mechanism Earliest Deadline First(EDF) Weighted Fair
Queue(WFQ)
Slide 41
Background Review 41 Earliest Deadline First(EDF)
priority-driven preemptive Job with earliest (absolute) deadline
has highest priority does not require knowledge of execution times
Execution profile of two periodic tasks Process A Arrives02040
Execution Time101010 End by204060 Process B Arrives050100 Execution
Time252525 End by50100150
Slide 42
Background Review 42 Weighted Fair Queue scheduling(WFQ) Packet
by Packet GPS(General Processor Sharing) GPS(General Processor
Sharing) concept Each flow i has a weight i and receives at least
r* i / ( k ) bits/s capacity of the outgoing link of capacity r
[bits/s]
Slide 43
Leaky bucket algorithm 43 Leaky bucket algorithm 1. often use
in ATM network 2. a traffic control mechanism 3. packets are
discarded when bucket overflows 4. output rate is a constant rate.
Leaky bucket algorithm parameters L : packet leak rate B : Bucket
Size(bytes) B/L : maximum latency at transmission
Slide 44
Leaky bucket algorithm 44 Note Leaky bucket is used in ATM,
where B and L be specified in units of cells and cells per
second
Slide 45
Token bucket algorithm 45 Token bucket algorithm 1. often use
in ATM network 2. a traffic control mechanism 3. Each packet
requires abstract tokento be sent Token bucket algorithm parameters
b : bucket size r : token input rate p : peak rate
Slide 46
Token bucket algorithm 46
Slide 47
Token bucket algorithm example 47 parameters: MaxTokens=5
r=3
Slide 48
Modified leaky bucket algorithm 48 Modified leaky bucket
algorithm : : / : frame Concept frames packet fragmentation frame
different cycle time data
Slide 49
Modified leaky bucket algorithm 49 Divide in two step (1) (2) A
B (1) (2) ( frame )
Modified leaky bucket algorithm 52 (1) WIMAX network MS Divide
in to branch A B
Slide 53
Modified leaky bucket algorithm 53 A B NOTE B ( bucket
limit)
Slide 54
54 Challenge Issues
Slide 55
55 QOS mapping WIMAX EPON QOS mapping EPON class mapping WIMAX
class EPON ONU queue WIMAX class mapping
Slide 56
Challenge Issues 56 service class starvation QOS EPON WIMAX
queue priority base DBA service class starvation QOS service class
starvation
Slide 57
57 Future Work
Slide 58
Future work 58 Simulation Solve challenge issues
Slide 59
59 Q&A
Slide 60
Reference 60 [1] IEEE Std 802.3ah-2004, IEEE Standard for
Information technology- Telecommunications and information exchange
between systems-Local and metropolitan area networks-Specific
requirement-Part 3: Carrier Sense Multiple Access with Collision
Detection (CSMA/CD) Access Method and Physical Layer
Specifications, September 2004. [2 ] IEEE Std 802.16-2004, IEEE
Standard for Local and metropolitan area networks-Part 16: Air
Interface for Fixed Broadband Wireless Access Systems,October 2004
[3] Gangxiang Shen, Rodney S. Tucker, and Chang-joon Chae, "Fixed
and Mobile Convergence Architectures for Broadband Access:
Integration of EPON and WiMAX, IEEE Commun. Mag., Aug. 2007. [4] G.
Kramer, B. Mukherjee, and G. Pesavento, "IPACT: A Dynamic Protocol
for an Ethernet PON (EPON)," IEEE Commun. Mag., vol. 40, issue 2,
pp.74-80, Feb. 2002 [5] Kun Yang, Shumao Ou, Ken Guild, and
Hsiao-Hwa Chen,"Convergence of Ethernet PON and IEEE 802.16
Broadband Access Networks and its QoS-Aware Dynamic Bandwidth
Allocation Scheme," IEEE JSAC, vol. 27, issue 2, Feb. 2009