The architecture and the protocols of LTE/EPC were designed to deliver high transmission rates with QoS requirements. In order to be able to guarantee different levels of QoS, each transmission is based on a bearer, which needs to be set up within the network. It then requires to store contexts in the various entities of the network and to set up several tunnels or connections both in the user and the control planes. This approach is, however, inadequate when considering a class of value-added services obedient to a “Short Data push principle”. This category which contains, at least, very popular services like Short Message Service (SMS) and Twitter, or new ones like Machine-to-Machine communication services, represents on one hand a continuously growing part of the worldwide amount of data traffic exchanged and on the other hand is easily recognizable thanks to its specific traffic pattern. To allow LTE/EPC to conveniently cope with the sporadic nature of these services, we introduce a new procedure based on a set of simple messages to transport such isolated messages only in the control plane. We show that this procedure may generate additional signaling in some cases but is efficient as soon as the proportion of sporadic traffic is not negligible. We illustrate our approach in the case of the SMS which is emblematic of the targeted category of services. The proposed procedure is, however, generic and may be used for any type of sporadic traffic.

Proxy mobile IPv6 (PMIPv6) has been developed as a network-based mobility management protocol by the Internet Engineering Task Force. Mobility for individual mobile nodes (MNs) is supported by network entities. PMIPv6 thus eliminates mobility signaling from the MNs as it does not require a mobility stack at the MNs. However, during handovers of MNs, PMIPv6 induces unnecessary location update traffic and suffers the packet loss, which downgrades the quality of mobility support. In this paper, we introduce a state-aware pointer forwarding scheme with fast handover support, called FC-PMIPv6, to further enhance the performance of mobility support in a PMIPv6 domain. In FC-PMIPv6, a pointer forwarding chain between mobility access gateways (MAGs) is established to reduce location update traffic to a local mobility anchor during handovers of an MN. The current mobility state of the MN is also considered in deciding whether the forwarding chain should be prolonged or refreshed by an MAG serving the MN. This mobility state consideration in pointer forwarding reduces unnecessary traffic for the location update and guarantees the efficiency of packet transmission. In addition, a fast handover process is adopted to reduce the handover latency and avoid the packet loss during handovers. We develop analytical models to study the performance of FC-PMIPv6, which consider both the signaling cost and the packet transmission cost. Numerical results not only demonstrate that FC-PMIPv6 outperforms the basic PMIPv6 protocol, but also present a relationship between an optimized length of a forwarding chain and a mobility state of an MN. From the conducted numerical results, for example, it is shown that the signaling cost of FC-PMIPv6 is enhanced up to 23% over the basic PMIPv6 protocol. In addition, simulation results on the weighted signaling cost are provided to demonstrate the performance improvement of our FC-PMIPv6 compared with the basic PMIPv6 protocol.

NEtwork MObility Basic Support (NEMO BS) is a standardized protocol for managing the mobility of a set of nodes that move together as a whole while having continuous connectivity to the Internet through one or more Mobile Routers (MRs). Because it is based on Mobile IPv6 (MIPv6), it inherits the properties of MIPv6, such as the use of IPsec. However, NEMO BS does not address all the features required by the demanding Intelligent Transportation Systems (ITS) scenario to provide an integrated and global secure mobility management framework. In addition, unlike MIPv6, the routing in NEMO BS is suboptimal, which makes difficult the provision of an adequate service performance. These characteristics make the application of the NEMO BS protocol not optimum in this scenario. An interesting strategy to provide security and good service performance is to consider a protocol that establishes and maintains Security Associations (SAs), such as the Host Identity Protocol (HIP). Different HIP-based approaches have been defined. However, these HIP-based network mobility solutions still present unsolved issues. In this article, we present a secure and efficient network mobility protocol named NeMHIP. NeMHIP provides secure and optimum mobility management and efficient end-to-end confidentiality and integrity protection apart from the basic security properties inherited from HIP. To evaluate the security provisions of NeMHIP, we have conducted a belief-based formal evaluation. The results demonstrate that the defined security goals are achieved by the protocol. Furthermore, we have performed an automated formal evaluation to validate additional security aspects of NeMHIP. Thus, we have modeled NeMHIP using the AVISPA tool and assessed its security when an intruder is present. The results confirm that NeMHIP is a secure protocol that ensures end-to-end confidentiality and integrity without introducing security leaks to the basic HIP. Thus, we have addressed the need found in the literature for providing security and efficiency in the network mobility scenario.

Cet article décrit l'interface radio LTE (Long Term Evolution). Il replace l'interface radio dans l'architecture générale, puis présente la notion de bloc de ressources, élément essentiel du mode paquet sur lequel repose LTE. L'article aborde ensuite les caractéristiques du signal transmis (bande de fréquence, duplexage, modulation, traitement d'antennes), la gestion des formats de transport et les structures liées au multiplexage temporel. A la suite, sont décrits les différents canaux physiques, qui permettent d'assurer l'accès d'un terminal au réseau (détection du réseau, synchronisation, accès initial et échange de données) et la couche MAC qui permet le multiplexage de différents flux et assure, grâce à un protocole de retransmission, un taux d'erreur modéré. Enfin, ce panorama se conclut par la présentation de RLC qui assure la qualité de service par des retransmissions si nécessaire et PDCP qui garantit la sécurité et permet la compression des données et des en-têtes.