Abstract: The society of 3rd Generation Partnership Project (3GPP) is completed developing Long Term Evolution Advanced (LTE-Advanced) systems as a standard 4G cellular system. This generation goals to produce conditions for a new radio-access technology geared to higher data rates, low latency, and better spectral efficiency. LTE-Advanced is an evolutionary step in the continuing development of LTE where the description in this article is based on LTE release 10. This paper provides a model of the traffic links of 4G system represented by LTE-Advanced system with the effect of the Transmission Control Protocols (TCP) and Stream Control Transmission Protocol (SCTP) in term of throughput and packet loss. Furthermore, the article presents the investigation and the analysis the behavior of SCTP and TCP variants over the 4G cellular systems. The traffic model and the scenario of the simulation developed using the network simulator NS-2 using different TCP source variants.
Abstract: Stream Control Transmission Protocol (SCTP) has been
proposed to provide reliable transport of real-time communications.
Due to its attractive features, such as multi-streaming and multihoming,
the SCTP is often expected to be an alternative protocol
for TCP and UDP. In the original SCTP standard, the secondary path
is mainly regarded as a redundancy. Recently, most of researches
have focused on extending the SCTP to enable a host to send its
packets to a destination over multiple paths simultaneously. In order
to transfer packets concurrently over the multiple paths, the SCTP
should be well designed to avoid unnecessary fast retransmission
and the mis-estimation of congestion window size through the paths.
Therefore, we propose an Enhanced Cooperative ACK SCTP (ECASCTP)
to improve the path recovery efficiency of multi-homed host
which is under concurrent multiple transfer mode. We evaluated the
performance of our proposed scheme using ns-2 simulation in terms
of cwnd variation, path recovery time, and goodput. Our scheme
provides better performance in lossy and path asymmetric networks.
Abstract: True integration of multimedia services over wired or
wireless networks increase the productivity and effectiveness in
today-s networks. IP Multimedia Subsystems are Next Generation
Network architecture to provide the multimedia services over fixed
or mobile networks. This paper proposes an extended SIP-based QoS
Management architecture for IMS services over underlying IP access
networks. To guarantee the end-to-end QoS for IMS services in
interconnection backbone, SIP based proxy Modules are introduced
to support the QoS provisioning and to reduce the handoff disruption
time over IP access networks. In our approach these SIP Modules
implement the combination of Diffserv and MPLS QoS mechanisms
to assure the guaranteed QoS for real-time multimedia services. To
guarantee QoS over access networks, SIP Modules make QoS
resource reservations in advance to provide best QoS to IMS users
over heterogeneous networks. To obtain more reliable multimedia
services, our approach allows the use of SCTP protocol over SIP
instead of UDP due to its multi-streaming feature. This architecture
enables QoS provisioning for IMS roaming users to differentiate IMS
network from other common IP networks for transmission of realtime
multimedia services. To validate our approach simulation
models are developed on short scale basis. The results show that our
approach yields comparable performance for efficient delivery of
IMS services over heterogeneous IP access networks.