The Design of power saving mechanisms in Ethernet Passive Optical Networks презентация

Chiang
Advisor: Prof Dr. Ho-Ting Wu
2013.10.28

Design of Power Saving mechanisms in Ethernet Passive Optical Networks
Two energy-modes in ONU
Add doze mode in ONU
Improve three energy-modes in ONU
Clockwise three energy-modes switching
Counterclockwise three energy-modes switching
Upstream scheduling
Downstream scheduling
Simulation result
Conclusion

Optical network terminals (ONTs)
Use broadcast on Downstream
Use TDMA on Upstream
All ONUs register to OLT with LLID

to the DBA algorithm
GATE
After executing DBA algorithm, OLT transmits GATE down-stream to issue up to four transmission grants to ONU
Transmission start time
Transmission length
Timestamp (used by ONU for synchronization)

Byte and RTT
First grant, G(1), is set to some arbitrary value
In polling cycle n, ONU measures its backlog in bytes at end of current upstream data transmission & piggybacks the reported queue size, Q(n), at end of G(n)
Q(n) used by OLT to determine next grant G(n+1) => adaptive cycle time & dynamic bandwidth allocation
If Q(n)=0, OLT issues zero-byte grant to let ONU report its backlog for next grant

energy-modes in ONU
Add doze mode in ONU
Improve three energy-modes in ONU

Lee, "Efficient PON with Sleep-Mode ONU: Progress, Challenges, and Solutions," refer two energy-modes including active and sleep modes. They separate high/low priority packet.

receive GATE msg. from OLT

priority data delay

data won’t trigger sleep ONU wake.
Doze mode can make OLT send downstream data earlier.

even no downstream data.
Low doze mode utilization
Active mode can’t turn to doze mode when no downstream data.

data when OLT get ONUx’s REPORT.

A -> D
[2] No upstream data but has downstream data when OLT get ONUx’s REPORT.

S -> A
[3] Upstream high priority data coming
// Early wake up

S -> D
[4] Stay at sleep mode for consecutive Y clock
// variable Y protects downstream high priority data，Y is maximum of downstream high priority data delay.

consecutive Z clock || upstream high priority data coming
// Timer avoids upstream long low priority data delay
// variable Y、Z protects upstream low priority data ， Y + Z is maximum upstream low priority data delay

p.s.
Active mode trigger: If report msg. request bandwidth = 0, means no upstream data.

downstream data when OLT get ONUx’s REPORT.

A -> D
[2] No upstream data but has downstream data when OLT get ONUx’s REPORT

S -> A
[3] Stay at sleep mode for Y clock || upstream high priority data coming
// variable Y protects downstream high priority data，Y is maximum of downstream high priority data delay.

consecutive Z ms
// Force
// Timer avoids upstream long low priority data delay
// variable Y、Z protects upstream low priority data ， Y + Z is maximum upstream low priority data delay
// Switch from Doze mode to Sleep mode is no delay so downstream high priority data increase Y clock delay, it’s maximum of downstream high priority data delay

D -> A
[5] upstream high priority data coming
// early wake up
p.s.
Active mode trigger: If report msg. request bandwidth = 0, means no upstream data.

bytes, but no more than MTW
OLT polling table increase ONU state.

have some relationship.
Different from general EPON, because ONU[x] in sleep mode, OLT can’t send downstream data. Downstream scheduling need to be considered.
ONUs’ doze mode maybe overlap so OLT need to select one of ONUs to send downstream data.

10MByte
EPON Frame size = 64Bytes ~ 1518 Bytes
Channel capacity = 1Gbps
Max rate = 100 * 1000 * 1000 = 100Mbps
Guard time = 5 * 10-6
Y : After 20ms the state from sleep to doze
Z : After 30ms the state from doze to active
Simulation time 3s

1%

downstream data delay in power saving EPON.
In order to raise up doze mode utilization, we design new three energy-modes switching mechanisms to increase it.
All results discuss between power saving and performance, it’s trade off. Maybe we can improve traffic scheduling or switching mechanism for future.

an Ethernet PON (EPON),” IEEE Communications Magazine, February 2002.
[2] Lei Shi, Biswanath Mukherjee and Sang-Soo Lee “Energy-Efficient PON with Sleep-Mode ONU: Progress, Challenges, and Solutions,” IEEE Network March/April 2012 pp. 36-41.
[3] Jingjing Zhang and Nirwan Ansari “Toward Energy-Efficient 1G-EPON and 10G-EPON with Sleep-Aware MAC Control and Scheduling,” IEEE Communications Magazine February 2011 pp. s34-38.