Research On Radio Resource Management Schemes In Heterogeneous Wireless Networks Based On Multiservice

The wireless communication technology is developing very rapidly these years. In the future, the wireless communication networks can be visualized as the integration of different radio access technologies (RATs), which are referred to as heterogeneous wireless networks (HWNs). Different RATs have their advantages and limitations. The co-deployment of HWNs can lead to larger capacity, lower cost and better quality of services (QoS).As the main standard in3GPP, LTE have a wide coverage area, but there is a limitation in bandwidth and data rate. WLAN provides higher bandwidth and data rate only within hotspots. The high speed data service like mobile multimedia is increasing rapidly especially in hotspot area. As a supplement method of LTE, WLAN can solve the problem of overload in cellular network. In the future, people will focus on the co-deployment of LTE and WLAN.This paper proposes some schemes for users in hotspot to utilize the resources in the HWNs and then analyzes the performances by means of system level simulation. This paper proposes two transmission schemes for data service, packet split scheme and entire packet scheme. In packet split scheme, the packet is split into two sub-packets and transported to the user over two networks at the same time. However, in the need of decoding, the user has to wait until all the sub-packets are received. Simulation results show that dual mode users are not suitable to transmit data in two networks simultaneously. In entire packet scheme, network selection is based on channel condition of users, which increases system throughput effectively. Dual mode users can only utilize WLAN to transmit data, which also achieves a good performance. When data service and voice service exist together, two schemes are proposed-always WLAN scheme and service based scheme. In always WLAN scheme, the user will connect to WLAN network as long as it’s available to him. This scheme is not good because it only concerns on data rate without considering delay-sensitive voice traffic. In service based scheme, users with voice services only connect to LTE because LTE guarantees these users’ demand for delay. For users with data services, if a WLAN connection is possible, it will be chosen. Simulation results are satisfying because this scheme considers both location and service type.