1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER
Title: Multi-Radio Power Management
Date Submitted: November, 2007
Presented at IEEE session #23, Atlanta
Authors or Source(s): Behcet Sarikaya (Huawei),
Abstract: Multi-Radio Power Management SG TR Discussion

2. IEEE 802.21 presentation release statements
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The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual < and in Understanding Patent Issues During IEEE Standards Development

3. 802.21 Multi-Radio Power Management Study Group Analysis

4. Assumptions Interface modes Active or powered on
Sleep or idle with paging channel on
Powered off
Interface power 70% of total power
Multi-radio usage more mainstream
Source: mobisys 2006

5. Powering Off Interfaces
First proposed in 1997
Turn off the network interface after the user has been in a think phase for more than a certain amount of time (called the attention span)
During Web surfing

6. Wake on Wireless Source: MSR The Problem
To receive a phone call the device and the wireless NIC has to be in a “listening” state i.e. they have to be on.
Proposal
When not in use, turn the wireless NIC and the device off.
Create a separate control channel. Operate the control channel using very low power, possibly in a different freq. band. Use this channel to “wake-up” device when necessary.
Proof of Concept & Implementation
Short Term: Add a low power RF transceiver to the enabled handheld device
Long term: Integrate lower power functionality into or integrate lower power radio into mother board and/or Access Points.
Source: MSR

7. Wake on Wireless
Results in improvement of 115% standby battery life-time of the handheld device
Even if interface was used in power save mode
Much higher (180%) if interface is used in the active mode
For a typical user with 82 minutes/day use, the gains translate into an improvement of over 40% higher battery life-time
Source: mobicom 2002

8. Coolspots
In wake on wireless, the lower-power radio is used as paging channel to only wake up the higher-power interface
It is also possible to use all interfaces to receive data
Higher-power interface is switched off when there is too much unused bandwidth available and the lower-bandwidth radio is used (switch down)
When there is too little bandwidth available in lower-power radio channel, the higher-power radio is power on and the lower-power radio could be turned off or it could be kept powered on (switch up)
Dynamic switching policy can reduce energy consumption of the wireless interface by 75%, without significantly increasing the overall delay
Source: mobisys 2006

9. Paging: Problem or Solution?
Paging is part of the solution to Power Management in cellular interfaces
We did not state anywhere that paging is a problem
Paging aggregation/via connected radio is a problem

10. Use Cases: Solutions?
The use cases show example flows using real entities
On the other hand:
MRPM Solution will amend
MRPM Solution has to deal with the entities defined in

11. Q & A?