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 multiradio 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
1
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2
Agenda
•Motivation
•Existing single radio paging schemes
•Paging in multi-radio environment
•Proposed SG scope and work
3
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…
4
Use Case of Idle Mode & Paging with a single Radio
Paging
Data packets
Paging
Controller
Paging
Paging
Paging
Exit Idle Mode
Location Update
Data packets
Enter Idle Mode
Idle Mode
messages
5
3GPP- LTE Paging
•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
3GPP-LTE Network Architecture
MME/UPE
3GPP-LTE Paging Protocols
UE
MME/UPE
eNBs in TA
MME/UPE
EPC
User Data
Buffer
data
S1
Check UE
state, TA
Paging Message
Paging Message
E-UTRAN
X2
Paging Response
Paging Response
UP establishment
eNB
eNB
X2
Encrypted data
X2
eNB
6
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.
7
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 reassociation
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
Paging group #1
Paging Server #1
AP
AP
AP
AP
AP
AP
AP
Paging Server #2
AP
AP
AP
AP
AP
AP
Paging group #3
Paging group #2
AP
8
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
9
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
10
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
WLAN
Access
Point
CSN HAAA
ASN
GW*
CSN
ASN
BS
ASN
GW
HA
11
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
12
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
13
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.
14
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-idlemode.ppt, by Emily Qi et al
•11-07-0058-01-000v-paging-power-saving-analysisupdate.ppt, by Emily Qi et al
15
Backup
16
Paging via “connected” radio
•Scenario
– User is browsing on the WiFi interface
– User gets a voip call on the WiMAX interface.
– WiMAX network needs to page the user
•MS receiving Paging Announcement
Primitives: IEEE 802.21
•Possible Contents: Paging and Paging
Media/Radio Interface
1a
•BS/AP Paging Announcement
Primitives: IEEE 802.21
•Possible Contents: Paging and Paging
Media/Radio Interface
Is your radio in connected
mode in MS_a?
Yes! r_k is in connected
mode in MS_a
3
4
5
Is your radio in connected
mode in MS_a?
1b
2
MSG #1, #2,
#3, #4, and
#5: IETF
Inter PC co-ordination
Paging announce on r_k
to turn on r_i
Paging announce on r_k
to turn on r_i
MS_a
BS/AP
of radio r_k
PC
of radio r_k
PC
of radio r_i
PC of r_j
17
Location Update via “connected” radio
•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
•MS Location Update Request/Response
Primitives: IEEE 802.21
•Possible Contents: Paging and Paging
Media/Radio Interface, Location Information
LU for r_k
•BS/AP Location Update Request/Response
Primitives: IEEE 802.21
•Possible Contents: Paging and Paging
Media/Radio Interface, Location Information
(sent on radio
r_i)
LU for r_k
(sent on radio
r_i)
LU for r_k
(sent on radio r_i)
All MSGs: IETF
LU_RSP for MS
LU_RSP for MS
LU_RSP for MS (sent on
r_i)
BS/AP
of radio r_i
PC
of radio r_i
PC
of radio r_k
18
Aggregated Location Update
•If the PGs are overlapping, perform a single LU operation for multiple radios.
•Minimizes messaging and processing at the MS
Extended
Location
Update
Message for
Multi radio:
IEEE 802.16,
802.11
LU for r_i,j,k (sent on
radio r_i)
LU for r_i,j,k (sent on
radio r_i)
MSGs: IETF
LU for r_k (sent on radio r_i)
LU for r_j (sent on radio r_i)
LU_RSP for MS
LU_RSP for MS
LU_RSP for MS
LU_RSP for MS (sent on
r_i)
MS
BS/AP
of radio r_i
•MS Location Update
Request/Response Primitives:
IEEE 802.21
•Possible Contents: Paging and
Paging Media/Radio Interface,
Location Information
PC
of radio r_i
PC
of radio r_j
PC
of radio r_k
•BS/AP Location Update
Request/Response Primitives: IEEE
802.21
•Possible Contents: Paging and
Paging Media/Radio Interface,
Location Information
19
Paging-aggregation
•Page on a single idle radio to wake up multiple idle radios.
•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
Paging on r_i (meant for
radios r_i,j,k)
1
Extended Paging
Announcement Message
for Multi radio: IEEE
802.16, 802.11
Paging on r_i (meant for
radios r_i,j,k)
IM exit for r_i,j,k
MS
BS/AP
of radio r_i
PC
of radio r_i
BS/PC
of radio r_j
BS/PC
of radio r_k
20
•Scenario: Multiple radios are switched to idle mode
Idle mode Entry/Exit–
Extended Idle Mode
Request/Response messages
for Multi radio: IEEE 802.16,
802.11
1
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.
IM_entry for r_i, r_j, r_k
(sent on radio r_i)
2
IM_entry for MS on r_i, r_j,
r_k (sent on radio r_i)
3
IM_entry for MS
MSGs: IETF
IM_entry for MS
4
5
IM_entry_RSP for MS
(paging parameters for r_j)
6
IM_entry_RSP for MS (contains paging params for r_k)
7
8
MS
IM_entry_RSP for MS
(paging params for r_i,j,k)
IM_entry_RSP for
MS(paging params for
r_i,j,k)
BS/AP
of radio r_i
•MS Enter/Exit Idle Mode
Request/Response
Primitives: IEEE 802.21
•Possible Contents: Paging
and Paging Media/Radio
Interface, Location
Information
PC
of radio r_i
PC
of radio r_j
PC
of radio r_k
•BS/AP Enter/Exit Idle Mode
Request/Response Primitives:
IEEE 802.21
•Possible Contents: Paging and
Paging Media/Radio Interface,
Location Information
21
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).
22
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
23
Comments/ Concerns
•There are potentially several security issues to consider
especially when networks cross operator administrative
domains
– IPSec and IKEv2 available and widely used
24
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
25
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
26
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
27
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
28
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.
29