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Mobility using IEEE 802.21 in a Mobility using IEEE 802.21 in a heterogeneous IEEE 802.16/.11-heterogeneous IEEE 802.16/.11-

based, IMT-advanced [4g] network based, IMT-advanced [4g] network

Les Eastwood and Scott Migaldi, MOTOROLAQiaobing Xie

Vivek Gupta, INTEL

IEEE Wireless Communications Magazine, 2008

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Outline Outline • Introduction

– 4G, IMT, and IEEE 802: Terminology and History

• Handover Scenarios in a Dual Air Interface IMT-Advanced System

IEEE 802.21: Media-Independent Handover Services

• Modifying the 802.11, 802.16, and IETF MISHOP Standards to support 802.21

• A Note on 3GPP’s VCC and UMA Handover Mechanisms Applied to 802.16/802.11

• Conclusions

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Introduction Introduction • For the fourth generation (4G), the International Tele

communications Union — Radio Standardization Sector (ITU-R) sees a need for new wireless access technology.– must support data rates much higher than IMT-2000’s (or

3G’s) 30 Mb/s maximum.

• International Mobile Telecommunications (IMT) standards– IMT-2000 2.5G or 3G, – Enhanced IMT-2000 3.5G– IMT-Advanced 4G

• previously called “Systems beyond IMT-2000”

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IntroductionIntroduction (cont.) (cont.)

• IMT-Advanced targets peak data rates of about 100 Mb/s for highly mobile access (at speeds of up to 250 km/hr), and 1 Gb/s for low mobility (pedestrian speeds or fixed) access.

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ITU-R Rec. M.1645, “Framework and Overall Objectives for the Future Development of IMT-2000 and Systems Beyond IMT-2000,” June 2003.

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IntroductionIntroduction (cont.) (cont.)

• IEEE 802.16m – for a highly mobile (250 km/h) high-data-rate (100 Mb/s)– alone fails to meet the ultrahigh-data-rate (1 Gb/s) low-mobility require

ment

• IEEE 802.11 VHT– very high throughput– Data rates up to 1 Gb/s at stationary or pedestrian speeds.

• Together, 802.16m and 802.11 VHT will satisfy the requirements of IMT-Advanced systems.

• However, a dual-radio proposal needs a way to tie the two radio systems together into one.– smooth handovers or “seamless mobility”

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IntroductionIntroduction (cont.) (cont.)

• IEEE 802.21 provides the “glue” at layer 2 (or “layer 2.5

”) to make the two radio technologies work together as one.

• IEEE 802.21 adds value in a 4G environment– supports media-independent handover services to/from no

n-IEEE 802 radios• there will be many radio access technologies in 4G• supply of suitable spectrum will cause 4G to use multiple radios op

erating in fragmented bands.• ITU-R has adopted six IMT-2000 air interfaces.

– Five are cellular and one, IEEE 802.16 or WiMAX, is an IEEE standard.

– specifies services to reduce latency or otherwise optimize handovers

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Handover Scenarios in a Dual Air Handover Scenarios in a Dual Air Interface IMT-Advanced SystemInterface IMT-Advanced System

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• applications’ needs will be one driver for requirements on handover latency.– Provisions should be put in place to

allow gracefully exiting/pausing an application whose performance fails to satisfy.

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IEEE 802.21: Media-Independent IEEE 802.21: Media-Independent Handover ServicesHandover Services

• Contribution:– A framework that enables seamless handover between

heterogeneous technologies.– The definition of a new link layer SAP

• offers a common interface for link layer functions and is independent of the technology specifics.

– The definition of a set of handover enabling functions • provide the upper layers with the required functionality to perform

enhanced handovers.

Antonio de la Oliva, Albert Banchs, Ignacio Soto, Telemaco Melia and Albert Vidal, “An Overview of IEEE 802.21: Media-Independent Handover Services,” IEEE Wireless Communications Magazine, 2008.

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IEEE 802.21: Media-Independent IEEE 802.21: Media-Independent Handover Services Handover Services (cont.)(cont.)

• Secondary goals:– Service continuity

• the continuation of the service during and after the handover procedure.

– Handover-aware applications.• provides applications with functions for participating in handover d

ecisions.

– QoS-aware handovers• provides the necessary functions in order to make handover decisi

ons based on QoS criteria.

– Network discovery– Network selection assistance– Power management

Antonio de la Oliva, Albert Banchs, Ignacio Soto, Telemaco Melia and Albert Vidal, “An Overview of IEEE 802.21: Media-Independent Handover Services,” IEEE Wireless Communications Magazine, 2008.

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Qazi Bouland Mussabbir, Wenbing Yao, Zeyun Niu and Xiaoming Fu, “Optimized FMIPv6 Using IEEE 802.21 MIH Services in Vehicular Networks,” IEEE Transactions on Vehicular Technology, 2007

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IEEE 802.21: Media-Independent HaIEEE 802.21: Media-Independent Handover Services ndover Services (cont.)(cont.)

• Implementation issues– integrating IEEE 802.21 with existing link layer standards

will take time to complete.• Partial (vs. full) implementation of 802.21 services can still be

useful. See Table 3

– how to build support for IEEE 802.21 in network components. Figure 4

– operator deployment of IEEE 802.21• Collecting and maintaining information about all access networks

is a significant deployment challenge.– Static vs. dynamic

– business relationships

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A Note on 3GPP’s VCC and UMA Handover A Note on 3GPP’s VCC and UMA Handover Mechanisms Applied to 802.16/802.11Mechanisms Applied to 802.16/802.11

• Voice call continuity (VCC) potentially applies to 802.16m/802.11 VHT handover.– voice call handovers between the circuit-switched (UMTS)

and packet-switched (IMS) domains.– data, video, and multimedia is beyond VCC’s current scop

e– adds a call control continuity function (CCCF) to trigger an

d control the handover event.• increases network complexity

– requires the mobile to be connected to both the source and target networks simultaneously

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A Note on 3GPP’s VCC and UMA Handover A Note on 3GPP’s VCC and UMA Handover Mechanisms Applied to 802.16/802.11Mechanisms Applied to 802.16/802.11

• 3GPP’s unlicensed mobile access (UMA, also known as generic access network)– does voice handovers between circuit-switched (GSM) an

d packet-switched (802.11) networks– inefficient tunneling approach

• GSM packets encapsulated within 802.11 ones.• does not handle data, video, and multimedia applications well, and

introduces new network entities

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Open issuesOpen issues

• the integration of 802.21 with the IP transport layer for layer 3 transport.

• the use of different transport technologies to carry 802.21 transactions– a layer 2 transport (802 networks) on the wireless link up t

o the PoA, and a layer 3 transport between the PoA and the PoS.

Antonio de la Oliva, Albert Banchs, Ignacio Soto, Telemaco Melia and Albert Vidal, “An Overview of IEEE 802.21: Media-Independent Handover Services,” IEEE Wireless Communications Magazine, 2008.

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Conclusions Conclusions • Meeting IMT-Advanced requirements for both 100 Mb/s mobil

e and 1 Gb/s fixed radio links requires at least two radio technologies.

• Ideally, particularly for real-time and streaming applications, the handovers should be imperceptible to the user.

• IEEE 802’s proposal for IMT-Advanced is likely to include both IEEE 802.16m for 100 Mb/s high-mobility connections and 802.11 VHT for 1 Gb/s at lower mobility.– provide the glue for such a proposal, by enabling seamless handovers

between these two radio systems (and for other cellular or IEEE 802 radios)

• Real-world use cases for such handovers – include responding to applications, operators, or users asking for high

er data rates, lower costs, higher quality of service, or improved traffic management, as well as to changes in mobility status or coverage.