Melvi Ulvan

The study of handover procedure in LTE-based femtocell network

Wireless systems have the capability to address broad geographic area without the costly infrastructure deployment. However, the main drawback resides in the bandwidth limitation and the coverage for single access point. The deployment of Femtocell as the promising wireless access technology becomes one of the possible solution. In this paper the handover procedure in femtocell network is studied. The 3GPP LTE based handover is analysed in three scenarios: hand-in, hand-out and inter-FAP. In addition, the reactive and proactive handover strategy is also proposed as the handover decision policy to diminish the very frequent and unnecessary handovers.

Handover procedure and decision strategy in LTE-based femtocell network

Wireless systems have the capability to serve users over broad geographic area without using a costly network infrastructure. However, the main drawback of these systems represents the bandwidth restrictions and coverage. Deployment of femtocell as the emerging promising wireless access technology becomes one of possible solution how to overcome some of the drawbacks. In this paper, we investigate the handover procedure in femtocell network considering, both types of handovers, horizontal and vertical. The 3GPP LTE based handover procedure is analysed for three scenarios: hand-in, hand-out and inter-FAP. In addition, the reactive handover decision policy, based on the prediction of user movement and the prediction of target-FAP, is proposed as a way to eliminate frequent and unnecessary handovers.

Delay Performance of Session Establishment Signaling in IP Multimedia Subsystem

In this paper we investigate and analyze SIP delay during the session establishment signaling process in the IMS system. The delay for end-to-end link scenarios such as WiMAX-to-WiMAX, UMTS- to-UMTS, UMTS-to-WiMAX and vice versa are examined. For the analysis, we consider three types of delays: transmission delay, processing delay and queuing delay. The results show that the main delay of session establishment signaling process is due to the processing delay. In addition, the lower channel rate in the UMTS network as well as IMS service rate has significant impact to the session establishment signaling delay. In this paper, we review and analyze the delay of the session establishment signaling process. We present the structure of session establishment signaling process that is based on the standard. We analyze the delay, not only during the IMS processes where the S-CSCF, P-CSCF, I-CSCF and HSS take part, but also the transmission delay and the delay when the SIP messages are queued in the network. The transmission delay is analyzed as end-to-end delay where the source terminal (ST) and the destination terminal (DT) are either UMTS or WiMAX terminals. In term of transmission delay, the RLC (Radio Link Control) delay at the UMTS network and the non RLC delay at the WiMAX network are considered. The queuing delay is analyzed for the M/M/1 scheme. We also examine which delay among the transmission, processing and queuing delays that contributes the most significant delay in the system.

The study of IMS functionality in femtocell environment

In this paper, the deployment of IMS functionality in femtocell environment is investigated and overviewed. Femtocell is a small cellular base station designed for use in residential or small business environments. It allows service providers to extend service coverage inside of our home, especially where the existing access is limited or unavailable. In the mean time, the IMS, as emerging framework of fixed and mobile convergence, provides the functionalities that accommodate current and future services in wired and wireless networks (e.g. voice, video and data transfers). Configuring the IMS framework in new approach of network architecture such as femtocell and designing the femtocell network to support IMS services is quite demanding. Some possible network design will be discussed. In this paper we concern on the investigation of IMS SIP signalling when it works on femtocell environment. Another critical issue such as the delay properties of session establishment signalling is also interesting to be discussed. The IMS-based and Cellularbased approaches for the integration of femtocells system and IMS core network are discussed.

IEEE802.16 MAC Management Messages: The overhead and efficiency analysis in mesh topology

This paper presents the analysis of MAC Layer (L2) in wireless broadband system based on WiMAX IEEE802.16. The analysis is focused on overhead and efficiency of MAC Management Message and derived for mesh topology. The Mesh topology is evaluated concerning both existing types of scheduling - centralized and distributed - and their performance is compared. Some parameters, which deduced to have considerable influences i.e. the number of subscriber stations in the network, number of hops, various modulation and coding, and length of MAC PDUs, are assigned as the overhead parameters. The results show those parameters have significant impact on the efficiency of MAC layer.

Analysis of Session Establishment Signaling Delay in IP Multimedia Subsystem

This paper investigates and analyzes SIP delay in the session establishment signaling procedure in the IMS system. We investigate the delay for end-to-end link scenarios such as WiMAX-to-WiMAX, UMTS-to-UMTS, UMTS-to-WiMAX and vice versa. The analyses consider three types of delays: transmission delay, processing delay and queuing delay. The obtained results show that the main delay of session establishment signaling process is due to the processing delay. In addition, the lower channel rate in the UMTS network as well as IMS service rate has significant impact to the session establishment signaling delay.