Cross-Layer Design of the Inter-RAT Handover between UMTS and WiMAX

In future mobile networks, different radio access technologies will have to coexist. IEEE 802.21 MIH (Media-Independent Handover) provides primitive mechanisms that ease the implementation of a seamless vertical handover (inter-RAT handover) between different radio access technologies. However, it does not specify any handover execution mechanism. The first objective of this paper is to propose a novel MIHF (Media-Independent Handover Function) variant, which is renamed interworking (IW) sublayer. IW sublayer provides a seamless inter-RAT handover procedure between UMTS and WiMAX systems. It relies on a new intersystem retransmission mechanism with cross-layer interaction ability providing lossless handover while keeping acceptable delays. The second objective of this paper is to design a new TCP snoop agent (TCP Snoop), which interacts with the IW layer in order to mitigate BDP (Bandwidth Delay Product) mismatch and to solve spurious RTO (Retransmission TimeOut) problems. The cross-layer effects on the handover performance are evaluated by simulations. Our results show that cross-layer interaction between IW layer and TCP Snoop smoothes the handover procedure for TCP traffics. Additionally, this novel inter-RAT cross-layer scheme has the merit of keeping existing TCP protocol stacks unchanged.

[1]  Kwan Lawrence Yeung,et al.  Hierarchical cache design for enhancing TCP over heterogeneous networks with wired and wireless links , 2000, Globecom '00 - IEEE. Global Telecommunications Conference. Conference Record (Cat. No.00CH37137).

[2]  Vipul Gupta,et al.  Freeze-TCP: a true end-to-end TCP enhancement mechanism for mobile environments , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[3]  Byeong Gi Lee,et al.  Rate-adaptive snoop: a TCP enhancement scheme over rate-controlled lossy links , 2006, TNET.

[4]  Jianfei Cai,et al.  Adding network-layer intelligence to mobile receivers for solving spurious TCP timeout during vertical handoff , 2006, IEEE Network.

[5]  Abed Ellatif Samhat,et al.  A Layer 2 Scheme of Inter-RAT Handover between UMTS and WiMAX , 2008, 2008 IEEE 68th Vehicular Technology Conference.

[6]  Abed Ellatif Samhat,et al.  Inter-RAT Handover Between UMTS And WiMAX , 2010 .

[7]  Feng Liu,et al.  Improving TCP Throughput over HSDPA Networks , 2008, IEEE Transactions on Wireless Communications.

[8]  Petri Mähönen,et al.  Evaluation of Handover Performance for TCP Traffic Based on Generic Link Layer Context Transfer , 2006, 2006 IEEE 17th International Symposium on Personal, Indoor and Mobile Radio Communications.

[9]  Charles E. Perkins,et al.  Mobility support in IPv6 , 1996, MobiCom '96.

[10]  Abed Ellatif Samhat,et al.  A Cross-Layer Scheme for Inter-RAT Handover from WiMAX to UMTS , 2008, IEEE GLOBECOM 2008 - 2008 IEEE Global Telecommunications Conference.

[11]  Michael Meyer,et al.  Performance evaluation of a TCP proxy in WCDMA networks , 2003, IEEE Wirel. Commun..

[12]  Abed Ellatif Samhat,et al.  A layer 2 scheme for inter-RAT handover between UMTS and WiMAX in tight coupling architecture , 2008, 2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications.

[13]  Suresh Singh,et al.  M-TCP: TCP for mobile cellular networks , 1997, CCRV.

[14]  Philippe Martins,et al.  Performance evaluation of L2 handover mechanisms, for Inter-Radio Access Networks , 2006, 2006 IEEE 63rd Vehicular Technology Conference.