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IEEE 802.21 MEDIA INDEPENDENT HANDOVER

DCN: 21-07-0055-00-0000-Multi-Radio-Paging

Title: Multi-Radio Paging Study Group Request

Date Submitted: March, 2007

Presented at IEEE 802.21 session #19 Orlando

Authors or Source(s):

Behcet Sarikaya, Phil Barber (Huawei)

Muthu Venkatachalam, Vivek Gupta, Emily Qi (Intel Corporation)

Benjamin Koh (Panasonic) Peretz Feder (Alcatel-Lucent)

Abstract: This presentation describes a few single radio paging environment and then introduces the need for supporting multi-radio paging. The aim is to propose that a Study Group be established to assess whether there is justification to form a task group to define a standard IEEE 802.21 Media Independent Paging Service in a multi-radio environment

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IEEE 802.21 presentation release statements

This document has been prepared to assist the IEEE 802.21 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 802.21.

The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual <http://standards.ieee.org/guides/opman/sect6.html#6.3> and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> 

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Agenda

•Motivation

•Existing single radio paging schemes

•Paging in multi-radio environment

•Proposed SG scope and work

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Motivation

•For a single radio MN, idle Mode and Paging have already been proposed independently in WiMax, 3GPP and WiFi to extend battery standby time

•In a multi radio environment, the MN may have multiple radios and each radio may be in “connected” or “idle” state. There is an opportunity to provide paging service via “connected” radio and aggregate paging messages across multiple radios

– Fewer paging messages across network infrastructure– Fewer number of active radios on MN

•Multi Radio Paging can lead to considerable power saving at the MN and also provide radio/network/device resource optimization at the mobile communication infrastructure

•More on the savings in backup slides…

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Use Case of Idle Mode & Paging with a single Radio

Data packetsData packets

Paging Paging ControllerController

Idle Mode Idle Mode messagesmessages

Enter Idle ModeEnter Idle Mode

Location UpdateLocation Update

Exit Idle ModeExit Idle Mode

PagingPaging PagingPaging

PagingPaging

PagingPagingData packetsData packets

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3GPP- LTE Paging

UE eNBs in TA MME/UPE

Buffer data

User Data

Check UE state, TA

Paging Message

Paging Message

Paging Response

Paging Response

UP establishment

Encrypted data

UE eNBs in TA MME/UPE

Buffer data

User Data

Check UE state, TA

Paging Message

Paging Message

Paging Response

Paging Response

UP establishment

Encrypted data

eNB eNB

eNB

MME/UPE MME/UPE

S1

X2

X2

X2

EPC

E-UTRAN

3GPP-LTE Network Architecture 3GPP-LTE Paging Protocols

•UE enters IDLE mode when there is no activity.

•Discontinuous Reception (DRX) – UE uses DRX in IDLE mode, i.e. wakes up periodically to check for paging messages.

•UE learns DRX cycle length upon network entry from the eNodeB.

•UE is registered at Tracking Area Level.

•Already exists in today’s networks

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WiMAX Paging

•Paging controller (PC) is a logical entity that administers activity of Idle mode MS. It may be co-located with BS or ASN Gateway. A PC may monitor one or more paging groups.

•Paging Agent (PA) entity, co-located with BS, handles the interaction between PC and paging functionality implemented in BS.

•Location Register (LR) is a database that contains information about Idle mode MSs.

•PC is responsible for sending paging messages and handling location updates.

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WLAN Paging•Currently no paging for WLANs but a proposal exists

•Idle Mode Operation– AP and Client advertises Paging Capability Discovery– Client enters Idle Mode if there is no incoming traffic– AP broadcasts Paging Indications (Paging ID), and client wakes up to receive paging indication– Client exits Idle Mode when client is paged

•Paging Group (PG) - a group of APs in which STA can be paged

– Provides a collection of BSSs which a Client may traverse without requiring re-association

– A Client must reassociate if it transitions to an AP in a different Paging Group•Paging Server

– Provides Paging Services and Serves one or more Paging Groups

AP

AP

AP

AP

AP

AP

AP

AP

AP

AP

AP

AP

AP

AP

Paging group #1

Paging group #2

Paging Server #2

Paging group #3

Paging Server #1

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Paging Summary in a single radio environment

For each individual radio:

•Key Paging Messages – Paging Capability Discovery – Enter/Exit Idle Mode– Location Update (sent by MN aka Idle Mode Update)

• MS sends location update to the infrastructure

– Paging Indication (sent by infrastructure)• MS periodically wakes up to check whether it is being paged or not

•Key Concept and Logical Entity – Paging Group or Paging Area– Paging Server or Paging Controller

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Multi-Radio Paging Potential Benefits

•In a multi-radio environment, the MN may have multiple radios and each radio may be in “connected” or “idle” states

•Potential Multi Radio Paging Benefits– All Paging messages via the “connected” radio

• Paging Indication Message sent via the “connected” radio• Location Update via the “connected” radio

– Paging aggregation minimizes message exchange• Paging Indication Message aggregation• Location Update aggregation• Idle Mode Enter/Exit aggregation

•Therefore, unified multi-radio paging primitives are needed for multi-radio environments

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Multi-Radio Paging Potential Benefits

•Tight-coupling solutions for 802.16 & 802.11 planned in future releases

•Multi-radio MN can enjoy benefits of location update on connected radio (WLAN), 802.16&802.11 idle mode entry using 802.11 radio, 802.16&802.11 paging on 802.11 radio

CSN

HA

HAAA

ASNGW*Access

Point

ASN

WLAN

ASNGW

Mul

ti-Rad

io N

IC

BS

CSN

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Multi-Radio Paging Potential Challenges

•There are potentially several security issues to consider especially when networks cross operator administrative domains

•There are issues around evolution of paging systems, does MRP, i.e. inter-operability restrict innovation in 3GPP LTE?

•Given that paging systems are evolving and new paging systems are very efficient, are the gains from MRP likely to be significant or very modest?

•Are there potentially issues on why MRP needs to function in L2?

•More details are in backup slides

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Objective

It is proposed that a Study Group be established to assess whether there is justification to form a task group to define a standard IEEE 802.21 Media Independent Paging Service in multi-radio environment

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Proposed SG Scope

•Identify and quantify multi-radio paging benefits

•Identify technical scope

•Determine impacts on IEEE 802.16, 802.11, and other standards, for example:

– Potential Remediation : Determine whether available mechanisms are economically feasible and of utility to the community

– Threat Analysis: Identify security threats especially when networks cross operator administrative domains

– MAC and IP layer message requirements: Identify the engagement with IEEE 802.16, 802.11, 802.15, 802.22, WiMAX, 3GPP LTE and 3GPP2

– IP layer message requirements: Identify the engagement with IETF

•Decide whether a TG is needed, and if so define PAR and 5Criteria.

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Reference

•21-06-0701-00-0000-Media independent idle mode and paging.ppt, by Muthaih Venkatachalam (Intel Corporation)

•11-07-0061-00-000v-presentation-paging-and-idle-mode.ppt, by Emily Qi et al

•11-07-0058-01-000v-paging-power-saving-analysis-update.ppt, by Emily Qi et al

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Backup

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Paging via “connected” radio

MS_aBS/AP

of radio r_kPC

of radio r_kPC

of radio r_i

1a

PC of r_j

Is your radio in connected mode in MS_a?

Is your radio in connected mode in MS_a?

Inter PC co-ordination

2

1b

3

5

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MSG #1, #2, #3, #4, and

#5: IETF

•BS/AP Paging Announcement Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface

•MS receiving Paging Announcement Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface

•Scenario– User is browsing on the WiFi interface – User gets a voip call on the WiMAX interface.– WiMAX network needs to page the user

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Location Update via “connected” radio

BS/AP of radio r_i

LU for r_k (sent on radio r_i)

PC of radio r_i

PC of radio r_k

LU for r_k (sent on radio r_i)

LU_RSP for MS

LU_RSP for MS (sent on r_i)

•User has WiFi connection that is currently active and WiMAX connection that is idle.

•Instead of contending on the WiMAX airlink, MS uses the WiFi radio to perform location update for its WiMAX radio

All MSGs: IETF

•BS/AP Location Update Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

•MS Location Update Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

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Aggregated Location Update

•If the PGs are overlapping, perform a single LU operation for multiple radios.

•Minimizes messaging and processing at the MS

BS/AP of radio r_i

LU for r_i,j,k (sent on radio r_i)

PC of radio r_i

PC of radio r_j

LU for r_i,j,k (sent on radio r_i)

LU for r_k (sent on radio r_i)

LU_RSP for MS

LU_RSP for MS (sent on r_i)

PC of radio r_k

LU_RSP for MS

MS

•BS/AP Location Update Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

•MS Location Update Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

MSGs: IETF

Extended Location Update Message for Multi radio: IEEE 802.16, 802.11

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Paging-aggregation

•Page on a single idle radio to wake up multiple idle radios.

MSBS/AP

of radio r_iPC

of radio r_iBS/PC

of radio r_j

1

BS/PC of radio r_k

IM exit for r_i,j,k

Extended Paging Announcement

Message for Multi radio: IEEE 802.16, 802.11

•MS receiving Paging Announcement Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface

•BS/AP Paging Announcement Primitives: IEEE 802.21Possible Contents: Paging and Paging Media/Radio Interface

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Idle mode Entry/Exit•Scenario: Multiple radios are switched to idle mode

– For example: when the user takes a break, his WiMAX, WiFi and 3G connections may go into idle mode

•IM Entry/Exit for radios i, j , k happens on radio-i.

MSBS/AP

of radio r_i

IM_entry for r_i, r_j, r_k (sent on radio r_i)

PC of radio r_i

PC of radio r_j

PC of radio r_k

IM_entry for MS on r_i, r_j, r_k (sent on radio r_i)

IM_entry for MS

IM_entry for MS

1

2

3

4

IM_entry_RSP for MS (paging parameters for r_j)

IM_entry_RSP for MS (contains paging params for r_k)

5

6

IM_entry_RSP for MS(paging params for r_i,j,k)

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IM_entry_RSP for MS(paging params for

r_i,j,k)8

MSGs: IETF

•MS Enter/Exit Idle Mode Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

•BS/AP Enter/Exit Idle Mode Request/Response Primitives: IEEE 802.21•Possible Contents: Paging and Paging Media/Radio Interface, Location Information

Extended Idle Mode Request/Response messages for Multi radio: IEEE 802.16,

802.11

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Proposed Standard Engagements

•IEEE 802.21: Standard Message Primitives– Paging capability Primitives– Location Update Primitives– Enter/Exit Idle Mode (Radio State update) Primitives– Paging Indication Primitives

•IEEE 802.16, 802.11, LTE (?): MAC layer messages– RAN specific Containers/Transport to carry above messages

•3GPP/WiMAX/IEEE: IP Layer messages (back end)– Messages between Paging Controllers – Between Paging Controller and PoA (BS/AP).

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Proposed Standard Engagements

•IETF:– MIPSHOP WG currently defining transport protocol for 802.21– MRP needs MIPSHOP WG liaison for any IP transport issues– MONAMI6 WG on multiple wireless interface host mobility– MRP may propose MONAMI6 WG liaison for any IP Paging issues

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Comments/ Concerns

•There are potentially several security issues to consider especially when networks cross operator administrative domains

– IPSec and IKEv2 available and widely used

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Comments/ Concerns (cont’d)

•There are issues around evolution of paging systems, does MRP, i.e. inter-operability restrict innovation in 3GPP LTE?

– MPR is not about individual paging systems, so paging systems can evolve independent of MPR

– The glues (IP layer backend messages) may need to be redefined

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Comments/ Concerns (cont’d)

•Given that paging systems are evolving and new paging systems are very efficient, are the gains from MRP likely to be significant or very modest?

•Multi-radio Paging gains are significant:– Due to resource allocation/ QoS, single-radio idle mode entry

requires at least 4 message exchange with two messages over the air; the same for idle mode exit

– For a 3 radio MN, Location update separately on single-radio requires a total of 3 * (4 + 4 + 4), 36 messages with 18 over the air

– Aggregated LU procedure of multi-radio paging using the connected radio requires only 8 messages with 2 over the air

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Comments/ Concerns (cont’d)

•Given that paging systems are evolving and new paging systems are very efficient, are the gains from MRP likely to be significant or very modest?

•Multi-radio Paging gains are significant:– Single-radio paging potentially involves many (n) BSs in the

same paging area broadcasting paging request messages. Only one BS reports success to the paging controller (PC), PC stops n-1 BSs

– Paging via connected radio procedure of multi-radio paging avoids the search and requires only two messages

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Comments/ Concerns (cont’d)

•There are potentially issues on why MRP needs to function in L2?

– The reasons are the same as for 802.21

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Motion

•Move that the IEEE 802.21 WG form a study group to determine how to formally describe the IEEE 802.21 Multi-Radio Paging functions and behaviors, with the intent to create a PAR and five criteria documents to form a new Task Group.