The Simulation Of Cross-layer Data Exchange Between LTE And WLAN Systems

WLAN (Wireless Local Area Networks) technology has received the widespread attention for its flexibility and mobility. It is rapidly developing and being widely applied. In view of product and development of the technology, WLAN is developing towards the following five directions:higher data transmission speed, more supports for streaming media, applications in composite modules, distributed intelligent management and safer mechanism. LTE (Long Term Evolution) is a long term evolution of UMTS (Universal Mobile Telecommunications System) technical standard ordered by the3GPP (The3rd Generation Partnership Project) organization. LTE system has introduced the OFDM (Orthogonal Frequency Division Multiplexing), multi-antenna MIMO (Multiple-Input Multiple-Output) and other key transmission technique. It significantly increases the spectral efficiency and system throughput, the system capacity and coverage are also improved greatly.Although the development of wireless communication becomes more and more quickly, at the same time, the user requirements for multimedia communication are also becoming stronger, such as the development of HD (High Definition) online video, video calls and the email with large attachments. Therefore, transmission rate will become the "bottleneck" of mobile communications. These services have raised higher requirements for the high-bandwidth, rapid access, high-performance of the mobile Internet. How to further improve the system throughput of mobile communications is a hot topic in the field of wireless technology. The topic is the focus of this paper.This paper completes the following work:(1) It analyses deeply the structure, functions and the technical specifications of both IEEE802.11wireless local area network and LTE network.(2) It designs the joint operation scheme of WLAN networks and LTE networks. In the scheme, the wireless nodes are composed by the LTE module and WLAN module. The WLAN module sharing the LTE network data flow reduces pressure of data flow for the LTE network. And both modules are connected by the WLAN data exchanger.(3) It completes the data exchanger. Data of sender branches in the data exchanger, respectively through the LTE, WLAN module to transfer. The LTE and WLAN module of receiver receive data respectively, and then recombine the data in WLAN data exchanger. It achieves improving the system throughput. (4)It builds the LTE and WiFi system, and ensures both systems could achieve the basic communication function. By the simulation results, both systems are proved that the parameters meet the standard definition.(5) Based on the above, the two modules connected by the data exchanger achieve exchanging the data. The simulation results show that the involved joint operation platform can increase the transmission rate and reduce the average time delay to improve the system efficiency. And the joint operation of the WiFi system and the LTE system could reduce the communication pressure and the station expenses.