LTE-A Interworking for Seamless Service Provisioning Angelos Michalas 1 , Aggeliki Sgora 1,2 , and Dimitrios D. Vergados 2 1 Technological Educational Institute of Western Macedonia, Greece 2 Department of Informatics, University of Piraeus, Greece Abstract—Following the Always Best Connection (ABC) prin- ciple of the 4th generation wireless networks users of mobile services would be provided with connectivity to the best access technology all the time. In such a context mobile devices are equipped with multiple radio interfaces allowing connectivity to the most suitable network environment based on users require- ments and operators policies. Seamless vertical handover plays the key role for mobility across various access networks offering service continuity to users. In this paper seamless handover solu- tions are presented between 3GPP (Third Generation Partnership Project) and non-3GPP wireless access technologies utilizing functionalities of the Evolved Packet Core (EPC) network of the LTE-A, as well as, of the IEEE 802.21 standard. The schemes presented provide low latencies while supporting services QoS constraints, as well as, user requirements and provider policies. I. I NTRODUCTION Next generation wireless networks consist of many hetero- geneous access technologies supporting various service types with different Quality of Service (QoS) constraints, as well as, user requirements and provider policies. In such a context, seamless mobility of subscribers across multiple mobile access networks (ANs) is a key issue to make the ”always-on” connectivity vision a reality. Seamless handover (HO) requires low latency of the mobility procedure and maintenance of the level of QoS provided by the source access network at the target access network. To achieve the demands for seamless mobility the 3GPP integrates non-3GPP access technologies to the 4G EPC [1] network (Figure 1), allowing transition in a transparent way across diverse wireless access technologies. As a result, non- 3GPP access networks including the WiMAX and WiFi share the architecture infrastructure of the 3GPP technologies such as LTE-A and legacy GPRS. The EPC is an all IP network providing access to packet data networks while it supports authentication, authorization, accounting, QoS reservation and VHO mechanisms to mobile terminal devices (UEs). Another solution for mobility transfer is specified by the 802.21 media independent HO (MIH) standard [2] which defines HO operations across different ANs. This architecture provides generic interfaces and primitives independent of the type of UEs and access networks to support link-layer events and network information retrieval. Several research papers that examine the above VHO mech- anisms may be found in the literature. In [3] a VHO scheme is presented between WiMAX and 3GPP ANs where a logical component is introduced which eliminates interconnectivity Fig. 1. The 3GPP EPC architecture. problems in the source network during VHO operation. How- ever such problems are resolved when the reactive scenario of fast handovers for proxy mobile IPv6 (FPMIPv6) [4] is used. In [5] an enhanced FPMIPv6 technique is proposed to improve the VHO operation using the EPC architecture. New messages are introduced to solve the problem of lack of information between the source and the target network. In [6] a solution combining the EPC and the 802.21 MIH standards is investigated to improve the handover procedure. However the steps of the VHO process are not described in the level of EPC commands and MIH primitives. In this paper we present an enhanced architecture based on the MIH framework complementing the EPC network to achieve seamless mobility transfer. The rest of the paper is structured as follows. Section II presents an overview of the EPC and the 802.12 MIH technologies, while Section III identifies the improvements achieved through the cooperation of EPC and MIH. In section IV initially a VHO scheme utilizing the functionalities of the EPC is presented whereas an enhanced scheme complementing EPC with MIH functionality follows. Finally, a performance evaluation of the two schemes in terms of signaling transmission cost is presented in Section V, while conclusions are drawn in Section VI. II. TECHNOLOGIES OVERVIEW A. The 3GPP Network Integration In Figure 1 the 3GPP EPC core network [1] connected to multiple radio ANs is presented. As it is shown the serving 2014 International Conference on Telecommunications and Multimedia (TEMU) 978-1-4799-3200-9/14/$31.00 ©2014 IEEE 138 Authorized licensed use limited to: University of Piraeus. Downloaded on January 05,2022 at 13:45:13 UTC from IEEE Xplore. Restrictions apply.