A Fair and Efficient Packet Scheduling Scheme for IEEE 802.16 Broadband Wireless Access Systems

This paper proposes a fair and efficient QoS scheduling scheme for IEEE 802.16 BWA systems that satisfies both throughput and delay guarantee to various real and non-real time applications. The proposed QoS scheduling scheme is compared with an existing QoS scheduling scheme proposed in literature in recent past. Simulation results show that the proposed scheduling scheme can provide a tight QoS guarantee in terms of delay, delay violation rate and throughput for all types of traffic as defined in the WiMAX standard, thereby maintaining the fairness and helps to eliminate starvation of lower priority class services. Bandwidth utilization of the system and fairness index of the resources are also encountered to validate the QoS provided by our proposed scheduling scheme

VoIP Performance over Broadband Wireless Networks under Static and Mobile Environments

ABSTRAC

Polaris

The error performance of the 2-tier star shaped Quadrature Amplitude Modulation scheme over K and KG fading channels are analyzed and evaluated. Novel closed form expressions for Symbol Error Rate (SER) have been derived for M-ary 2-tier circular Star QAM transmitted over the K and KG fading channels. The expressions derived are in the form of sum of single definite integrals of hypergeometric functions which are calculated using numerical methods. The expressions are validated by extensive Monte Carlo simulation. A simple relationship between SER and bit error rate (BER) is proposed and experimentally verified. Using the expressions for SER, the optimum values of ring ratio are calculated for various values of M. It has also been established that the error performance of 2-tier Star QAM is considerably superior to that of the M-ary Square QAM for high and moderate fading. General Terms

A Tiered Mobility Management Solution for Cellular/WLAN Integrated Networks with Low Handoff Delay

Abstract. Demand for the Internet services through GPRS/3G networks is proliferating day-by-day. But low bit rate puts constraints on multimedia or mobile business services. In contrast, Wireless Local Area Networks (WLANs) provide high bit rate with low deployment cost. Therefore, integration of these two complementary systems would be the focus of next generation wireless networks. However mobility and handoff management become the key issues for such integration. If a cellular operator deploys as Operator's IP network (OIN), it will be connected to GPRS at Gi interface and to the Internet through firewall. Alternatively, the Internet can be connected directly at Gi interface and OIN can be connected to the Internet. These connection mechanisms restrict on scalability due to large packet forwarding delay. In this paper, we propose a new way to integrate GPRS/UMTS, OIN and the Internet for better scalability and smaller packet delay. We deploy one gateway for users of cellular (GPRS/UMTS) and WLAN host. The gateway is in OIN and is connected directly with GGSN at Gi interface. The home agent functionalities are distributed in two level hierarchies within the OIN to reduce the packet and handoff delay. The proposed architecture would be useful for large network size