IEEE 802.21 MEDIA INDEPENDENT
HANDOVER
Title: 21-08-0230-00-mrpm-redefined-scenarios-presentation.ppt
Date Submitted: July 16, 2008
Presented at IEEE 802.21 session #27 in Denver
Authors or Source(s): Behcet Sarikaya (Huawei),
Dennis Edwards (CoCo), Anthony Chan
(Huawei), James Han (Motorola), Michael
Williams (Nokia), Scott Henderson (RIM)
Abstract: Redefined Scenarios Presentation
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IEEE 802.21 presentation release statements
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MRPCM Problem Statement (1)
• With advances in devices, networks and usage models, multiradio operation is becoming the norm for Mobile Nodes (MN).
• Each MN radio consumes power. The amount of power
consumed by a radio depends on the technology and the traffic
it carries.
• Example: iPhone 3G Battery Life
Voice (2G) = 600 minutes
Voice (3G) = 300 minutes
Web Browsing (WiFi)* = 428 minutes
Web Browsing (Edge)* = 343 minutes
Web Browsing (3G)* = 197 minutes
A-GPS = “insignificant affect”
*Anandtech \July 11th, 2008
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MRPCM Problem Statement (2)
• This is a power consumption graph of a typical isochrononous traffic flow
from WiFi VoIP, Interface power consumptions are not uniform.
• Even for the same technology, baseline power consumption is
implementation dependent and may be non-zero, cf. Wireless Wakeups
Revisited- Energy Management for VoIP over Wi-Fi SmartPhone
• All other things being equal, faster data rates are more energy efficient.
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MRPCM Problem Statement (3)
• Turning off all radios conserves the most power. Putting all radios in the
active state maximizes connectivity and minimizes response time.
• Battery capacity is proportional to temperature and inversely proportional to
discharge rate, charge cycle count, age, etc. The more radios that are on, the
higher the discharge rate and the smaller the battery capacity. Battery graphs
from.
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MRPCM Problem Statement (4)
• Each radio interface is independently power managed using network specific
mechanisms. Power consumption optimizations of individual access
technologies allow viable target services with acceptable battery life. Such
optimizations are neither global nor cooperative, cf.
https://mentor.ieee.org/802.21/file/08/21-08-0207-00-mrpm-powerconsumptions-in-baseband-processors.ppt
• Network interface power consumption is only one aspect of system power
consumption. Computational energy costs for things like packet encryption
also need to be considered Things like increased packet latency from CPU
clock scaling are also important, cf.
https://mentor.ieee.org/802.21/file/08/21-08-0197-02-mrpm-response-timein-different-modes-of-operation.ppt
• The problem is to allow global policy to guide an optimal selection of
operational radio interfaces that satisfies connectivity and latency
requirements while minimizing MN energy consumption.
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802.21 Overview
• With advances in devices, networks and usage models, multi-radio operation is
becoming the norm for Mobile Nodes (MN).
• IEEE 802.21 provides an abstract set of Media Independent Handover Services
(MIH) designed primarily to support vertical handovers (across heterogeneous
networks). These MIH services include handover initiation, network selection
and interface activation. Handovers within a single network are most efficiently
handled by the network itself, though the MIH protocol may be used to
communicate among homogenous network components.
• The MIH interfaces provide a generalized framework through which disparate
networks can be individually addressed and allow specifying higher level
handover standards in terms of the MIH framework.
• MIH policy enforcement is explicitly relegated to a Network Selection Entity
(NSE). NSE may reside on MN to support local handover policy, on the
network to facilitate centralized handover policy, or cooperative with
communication between client and network enabled by MIH. The MIH
Information and Event Services inform NSE policy decisions to enable more
effective Handover decisions. Policy decisions are affected through the MIH
Command Service.
• Designed for existing and evolving networks. Media specific changes closely
follow base 802.21 MIH Protocol by increasing the breadth of the media specific
interface.
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What MRPCM Can Do to Help?
• Extend 802.21 to…
• Provide a standard, generalized framework (a set of power saving enablers)
for minimizing multi-radio power consumption by querying and setting the
operating mode of a wireless network interface.
• Provide a set of metrics that allows users of the framework to consider
network throughput and energy consumption as policy inputs.
• Provide a mechanism for using MIH IS network PoA location, coverage
maps and MN location information to conserve power in out of coverage
areas. Such mechanism being also useful to emergency services.
• Provide a conceptual model for implementing Network Radio Proxies that
emulate a radio’s presence on a network while it is turned off.
• Maintain interoperability with and between IEEE 802 and non-802 networks
• The framework should allow operators and MN integrators to express
network and power management policy in the form of a connection manager
that is based on MRPCM enhanced 802.21 interfaces, cf.
https://mentor.ieee.org/802.21/file/08/21-08-0228-00-mrpmmrpm-augmenting-a-feature-for-mih.ppt
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MRPM Framework:
Get/Set Radio Operating Modes
• Abstract Radio Power Modes provide a mapping between an
existing 802.21 Link_Action request (LINK_POWER_UP,
LINK_LOW_POWER, LINK_POWER_DOWN) onto a
technology specific operating mode of a radio. List of Actions
may need to be extended.
• Enable power management policy enforcement.
• Each radio has an array, constructed by the MN manufacturer,
containing (non-transmitting) energy consumption values for
each ARPM.
• Need to extend 802.21 Link SAP to retrieve the profiles and to
return, as well as set, the current ARPM values.
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MRPM Framework:
Energy Consumption Metrics



The energy consumed by a the wireless network interface module (vs. TX output
power, IERP, etc.) is of primary interest to MRPM. There are many ways to express
this battery drain, including bit energy cost (nJ/b) = mW * J/Ws * us/b
= W*10-3 * J/Ws * s/b*10-6 = J/b*10-9 = nJ/b
These metrics allow NSE to consider network energy consumption as a policy
input; all other things being equal, choose the most energy efficient network. The
most energy efficient network is also likely to be the fastest one (small bit widths).
Extend MIH IS metrics to include network and link power consumption.
IE_NET_DATA_POWER_LOAD value is likely to be a fixed optimal value.
LINK_PARAM_GEN values are measured quantities that reflect recent network
conditions.
DATA_POWER_LOAD
UNSIGNED_INT(2)
The type used with the IE_NET_DATA_POWER_LOAD, expressing
power consumed, in mW, at the network IE_NET_DATA_RATE
Data Power Load
DATA_POWER_LOAD
A new value, 5, needs to be added to the list LINK_PARAM_GEN
options that specifies the power consumed, in mW, at the
LINK_PARAM_GEN option 0, Data Rate
Energy Consumption
UNSIGNED_INT(4)
A new value, 6, needs to be added to the list LINK_PARAM_GEN
options that specifies the energy consumed, in nJ, during the interval
used to determine the value of LINK_PARAM_GEN option 3,
Throughput
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MRPM Framework:
Using Location Services
•Enable the use of coverage models to leverage and expand the 802.21
IE_POA_LOCATION element.
•MN must be able to tell its location relative to, and independently of, any network
POA
•Coverage map from MIH IS and MN location combine to avoid scanning in out of
coverage areas by facilitating radio scheduling.
Triggers Minimize Connectivity Disruption during
Link Switching
• takes same time to do handoff
• trigger setpoints established to avoid spurious events may be set too far down the
gradient.
• trigger conjunction in context of coverage maps allows more informed reaction
(current high trigger && candidate detect)
•
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TR Scenario 6.6: Power Management in out of
Coverage Areas
• A MN will have no network connection when it is first turned on or when it
has moved out of the coverage range of all available networks.
• With no other knowledge, the MN must turn on all radios, to maximize the
chance of finding an appropriate network to connect with. In networks other
than WiMax, the radios are essentially in an Active RX mode while looking
for a network.
• MRPM could turn on a radio to scan for a network and then turn it off again
for some configurable interval if the scan discovered nothing.
• If a mode can determine its own location then when querying the MIH IS for
a list of proximate networks, an MN may specify an NGHB_RADIUS that
far exceeds the range of any of its network radio interfaces. In areas of
sparse network coverage an NSE may tell from the location and range data
returned by the MIH IS that, upon losing connection with the current
network, it will not be able to reconnect to another network for some
significant time. In this case, the NSE may turn off the radio on receipt of a
LINK_DOWN event
• Should an MN determine that, based on the MIH IS coverage map, it is
approaching the coverage area of a new network then it could turn on the
appropriate radio. A LINK_DETECTED event will be generated with the
network is discovered and a LINK_UP event will be generated when the
network is joined. At such time the network coverage map may be refreshed
by the MIH IS
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MRMP Framework:
Proxy Conceptual Model
• 802.21 is designed for existing and evolving Networks
• An MRPM Network Radio Proxy (NRP) is a network entity that MRPM will
define, cf. https://mentor.ieee.org/802.21/file/08/21-08-0226-01-mrpmmarket-need-for-mrpm.ppt
• An NRP must be accessible to an MN via a current network PoA. The NRP
makes it appear that a powered down radio on the MN has actually joined
the candidate network. An NRP thus maximizes the candidate network
availability while minimizing MN battery drain.
• The emulation of certain functions (e.g., MN location updates) are
technology specific operations and may require an NRP Agent (NRPA)
to exist on the PoA of such networks
• An NRP can be seen as an extension the Mobile IP Proxies that are
already widely deployed on several networks,
• An NRPA on the current network PoA will be needed to handle “keep
alives” without unnecessarily waking the MN, cf.
https://mentor.ieee.org/802.21/file/08/21-08-0229-00-mrpm-mrpm-powersave-topics.ppt
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NRP Conceptual Model
Current Network
Current
PoA & NRPA
MRPM
NRP
Candidate
PoA &
NRPA
MRPM
Enabled
MIH IS
MN
NSE
Candidate
PoA &
NRPA
MRPM
NRP
Candidate
PoA &
NRPA
Proxied Network
Multi-Radio Power Management Service Flow
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NRP Scenarios
• NRP enables MN location updates to make it appear
that a powered down radio on the MN is roaming and
updating its location
• NRP should enable this technology dependent
signaling
• NRP enables idle mode entry to make it appear that a
powered down radio is going to the idle mode
• NRP should enable this technology dependent
signaling
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Emulation Scenario: Location Update
Using Active Interface
• While a proxy session is active, the MN may move from the
coverage area of one PoA to another on the same network.
When such a situation is identified, the NSE sends a
PROXY_UPDATE to the NRP. The NRP would then change
the NRPA that represents the MN on the network.
• Should mobility cause the MN to switch to a third network then
the NSE will send a PROXY_MOVE message to the NRP,
notifying it of the network change.
• Should the MN leave the coverage area of the proxy network
then it will send a PROXY_LEAVE message to the NRP.
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TR Scenario 6.2: Location Update Using
Active Interface
• While a proxy session is active, the MN may move from the
coverage area of one PoA to another on the same network.
When such a situation is identified, the NSE sends a
PROXY_UPDATE to the NRP. The NRP would then change
the NRPA that represents the MN on the network.
• Should mobility cause the MN to switch to a third network then
the NSE will send a PROXY_MOVE message to the NRP,
notifying it of the network change.
• Should the MN leave the coverage area of the proxy network
then it will send a PROXY_LEAVE message to the NRP.
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TR Scenario 6.3: Idle Mode Signaling for
Multiple Interfaces
• After completing a network operation, the MN may decide that
it wants to turn off the radio and replace it with a proxy session.
This is accomplished by sending a PROXY_REPLACE
message to the NRP.
• Assuming simultaneously overlapping coverage, all but one
active radio may be replaced by a proxy service.
• Depending on the amount and kind of data passing through the
current network to the MN, the active radio interface may be
placed in a low power state other than off.
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TR Scenario 6.4: Waking a Radio Over
the Current Interface
• In TR Scenario 6.1, traffic destined for a turned off radio is
forwarded over the current interface instead.
• Alternately, the NSE may wake the turned off radio and have it
replace the proxy on the candidate network by sending a
PROXY_WAKING_UP message to the NRP. Once the radio
has replaced the proxy on the candidate network the proxy
session ends. The NSE may switch to the new radio or decide to
continue dual radio operation.
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TR Scenario 6.5: Parameters
Configuration of Idle Interface
• The establishment of a proxy session requires the exchange of
configuration information between the MN, the NRP and AAA
entity on the candidate proxy network.
• NSE may apply “spam” filters to incoming traffic destined to a
turned off radio, only waking the radio if it is of interest to the
MN.
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Network Radio Proxy Details
• NRP Service descriptions will need to be added to the
MIH _NET_CAPABILITIES.
• The MIH NSE communicates with the NRP using the
following message types:
PROXY_REPLACE,
PROXY_JOIN,
PROXY_LEAVE,
PROXY_UPDATE,
PROXY_MOVE,
PROXY_FILTER,
PROXY_TRAFFIC_PENDING,
PROXY_FORWARD and
• PROXY_WAKING_UP
•
•
•
•
•
•
•
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Considerations for 802.3
• TBD
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Considerations for 802.11
• TBD
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Considerations for 802.16
• TBD
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802.16 Amendments
NCMS Extension
Network Control and Management System
AAA Services
Paging Services
Idle Mode Services
Service Flow Id
/Connection Id
Management Services
Security Services
RF Transmission and
Synchronization Services
Mobility Management
Services
Multimedia Session
Management Services
Gateway and Router
Services
Media Independent
Handover Function
Services
Network Management
Services
Radio Resource
Management Services
Network Address
Management Services
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Inter-working Services
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Considerations for non-802 networks
• TBD
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Thank you.
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backup
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Apple iPhone 3G Battery Life
Standby = 18000 minutes
Audio playback = 1440 minutes
Video playback = 420 minutes
Voice (2G) = 600 minutes
Voice (3G) = 300 minutes
Web Browsing (WiFi)* = 428 minutes
Web Browsing (Edge)* = 343 minutes
Web Browsing (3G)* = 197 minutes
A-GPS = “insignificant affect”
*Anandtech \July 11th, 2008
Battery graphs from. WiFi VoIP power consumption graph.
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http://www.freepatentsonline.com/7133374.html
• http://www.cs.toronto.edu/~delara/courses/csc2228/papers/cool
spots.pdf
• http://www.wipo.int/pctdb/en/wo.jsp?wo=2007019556
• http://www.monarch.cs.rice.edu/monarch-papers/icnp2002.pdf
• http://citeseer.ist.psu.edu/sconyers98examination.html
• http://www.csr.com/egps/introduction.htm
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