1. Date Submitted: May 28, 2008 IEEE 802.21 MEDIA INDEPENDENT HANDOVER
DCN: mrpm
Title: MIH signaling in MRPM
Date Submitted: May 28, 2008
Authors or Source(s):
 Dennis Edwards for MRPM SG
Abstract: Investigation of Radio State Management for MRPM

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IEEE presentation release statements
This document has been prepared to assist the IEEE Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE
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. Currently the LINK_SAP provides a way to influence the power state of a radio:
Link_Action.request Link_Action.request (LinkAction, ExecutionDelay, PoALinkAddress) Link Action LINK_ACTION Specifies the action to perform. LINK_ACTION SEQUENCE( LINK_AC_TYPE, LINK_AC_ATTR ) LINK_AC_TYPE UNSIGNED_INT(1) An action for a link. The meaning of each link action is defined in Table C-5.
0: NONE
1: LINK_DISCONNECT
2: LINK_LOW_POWER
3: LINK_POWER_DOWN
4: LINK_POWER_UP 5-255: (Reserved)
Per DCN: xxxx , MRPM Based on Existing Power Management of WiFi, WiMAX, 3GPP, and 3GPP2, the following states exist:
Wifi: active, doze, sleep (802.11v draft), off
WiMax: active, sleep mode, idle mode, off
3GPP: connected, idle, off
3GPP2: active, control hold, suspended, dormant, off

4. How many power states should MRMP specify?
LINK_FULL_POWER (active/connectedl)
LINK_LOW_POWER_REGISTERED (Wifi doze, Wimax sleep, 3GPP idle, 3GPP2 control hold)
LINK_LOWER_POWER_REGISTERED (Wifi sleep, 3GPP2 suspended)
LINK_LOWER_POWER_UNREGISTERED (WiMax idle)
LINK_DORMANT (3GPP2)
LINK_OFF (off for all)
For radio for each power state allow user to querry:
Link type,
RX power consumption,
flag indicating radio is connected to a network,
transition time to full power state (could have TX power here in active state)
Need a way to retrieve above information on each radio. Is there a better set of information?
Sorry, but I’m not sure of the best way to specify it right now, will update presentation with better suggestion.
Assume for now that some mechanism exists.
How are link power info and control functions used?

5. Network B Network A rB1 Network A MN path along Roadway at speed S,
PfpB < PfpA
ThoA-B
ThoB-A
TfpB
TfpA
Scenario: MN travels along road. Sensors can detect node location at diamonds. MN can connect to network A through radio A, and network B through radio B. Radio A consumes more power than radio B when both are active. MN can maintain connection to network A (blue circles) but only barely: QoS would be violated if no handoff took place. Network B can satisfy QoS anywhere in coverage area (yellow circle). Networks A and B are otherwise equivalent according to policy metric. Network Selection Entity (NSE) has perfect knowledge and prefers to maximize connection time to network B to minimize MN power consumption. Radio A goes to sleep when Radio B is connected. Radio B is turned off again when Radio A is reactivated.
Tauth = time to preauthenticate to network, known by link type
Tfp = time for radio to go from off state to full on, know by transition time
Tho = time for handoff, known by link type combination
Tsleep = time radio is in low power mode but still recognized by the network
Ton = time radio is on
Tprep = max( Tauth, Tfp )
Pfp = average power consumed while active, known from MRPM list of power states
Psleep = average power consumed while in low power mode, known from MRPM list of power states
TauthB
TsleepA
TonB
Energy Savings = (TsleepA)(PfpA-PfpB-PsleepA) – (TonB – TsleepA)(PfpA+PfpB)

6. Energy Savings by Maintaining QoS = (TsleepA)(PfpA-PfpB-PsleepA)
Network B
rB2
Network A
rB1
Network A
MN path
along
Roadway
at speed S,
PfpB > PfpA
TprepB+ThoA-B
TfpA+ThoB-A
Scenario same as before except this time radio B consumes more energy than radio A. Handover to network B is required before reaching rB2 to maintain QoS. Energy savings < 0.
TsleepA
TonB
Energy Savings by Maintaining QoS = (TsleepA)(PfpA-PfpB-PsleepA)
– (TonB – TsleepA)(PfpA+PfpB)

7. If the condition can be satisfied then
Satisfying policy may cost battery life, even when NSE has perfect knowledge
rB1 is furthest distance from center of network B where handoff can occur due to range of radios.
rB2 is least distance from center of network B where handoff can occur due to QoS requirements of MN
Let rBP be the distance from the center of network B where policy action is to be affected by the NSE. In the first example rBP = rBPmax = rB1-Tho*S and in the second example rBp = rBPmin = rB2
The last point where an NSE can effectively initiate a handoff is at radius rB0 from the center of network B, where: rB0 >= rBP + (Tprep + Tho)*S
If the condition can be satisfied then
Tpolicy-discretion = (rBPmax – rBPmin)/S
Of course, this is a very simplified model but it does illustrate that MIH handoff signaling is “fast enough” if the notifications can be delivered to the MN on time.