1. 1 Mobility using IEEE 802.21 in a heterogeneous IEEE 802.16/.11- based, IMT-advanced [4g] network Les Eastwood and Scott Migaldi, MOTOROLA Qiaobing Xie Vivek Gupta, INTEL IEEE Wireless Communications Magazine, 2008

2. 2 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

3. 3 Introduction For the fourth generation (4G), the International Telecommunications 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”

4. 4 Introduction (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.

5. 5 ITU-R Rec. M.1645, “Framework and Overall Objectives for the Future Development of IMT-2000 and Systems Beyond IMT-2000,” June 2003.

6. 6 Introduction (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 requirement 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”

7. 7 Introduction (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 non-IEEE 802 radios there will be many radio access technologies in 4G supply of suitable spectrum will cause 4G to use multiple radios operating 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

8. 8 Handover Scenarios in a Dual Air Interface IMT-Advanced System

9. 9 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.

10. 10 IEEE 802.21: Media-Independent Handover 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.

11. 11 IEEE 802.21: Media-Independent Handover Services (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 decisions. –QoS-aware handovers provides the necessary functions in order to make handover decisions 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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15. 15 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

16. 16 IEEE 802.21: Media-Independent Handover Services (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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19. 19 A Note on 3GPP’s VCC and UMA Handover Mechanisms 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 scope –adds a call control continuity function (CCCF) to trigger and control the handover event. increases network complexity –requires the mobile to be connected to both the source and target networks simultaneously

20. 20 A Note on 3GPP’s VCC and UMA Handover Mechanisms 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) and 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

21. 21 Open 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 to 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.

22. 22 Conclusions Meeting IMT-Advanced requirements for both 100 Mb/s mobile 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 higher data rates, lower costs, higher quality of service, or improved traffic management, as well as to changes in mobility status or coverage.