Study Of Radio-over-Fiber Network Architecture Design And Key Technologies Of Medium Access Control Layer

The rapid growth of multi-service and huge bandwidth for customers’ communication demands, and the integration of the access networks are two driving forces for the development of radio-over-fiber (RoF) network. On one hand, fast-growing mobile multimedia services (including data, image, video and so on), increase sharply, as the emergence of high definition television, video telephone, game on line etc, and the universal use of intelligent phones and notebooks. It presents a multi-service and huge bandwidth communication demands. With the stimulation of the customers’demands, the access network evolutes to be a broadband, mobile, ubiquitous and green one. On the other hand, traditional wireless access networks support mobility, but can not supply the upcoming high bit-rate services and face a series of problems such as multipath interference, channel instability etc. Optical access networks can supply huge bandwidth, but are lack of ubiquitous access ability and can not meet the customers’mobile access requirements. According to this situation, integration of optical and wireless access network is becoming the development trend. Under this background, RoF network, in which wireless signals are transmitted through optical fibers, emerges at the right moment. It is widely concerned from domestic and international researchers, but still has series problems unsolved. In this dissertation, several research issues about the radio-over-fiber network architecture design and the medium access control (MAC) layer have been intensively investigated for the broadband ubiquitous, the high bit-rate and the low power consumption access demands, under the sponsorship of national863and973programs in China. Three representative application circumstances are chosen as research objects and the main works of this dissertation are summarized as follows:1) Research on the MAC protocol of IEEE802.11g based RoF networkAccording to the current situation that IEEE802.11g based wireless local access network are widely used, we intensively investigated the influence of the fiber delay caused by inserted fiber on its MAC protocol. With the proposed MAC protocol analyzing models, we investigates the MAC protocol perfonnance in the IEEE802.11g-over-Fiber network of different payloads and fiber lengths with two newly introduced physical layers (i.e. DSSS-OFDM, ERP-OFDM) using three access mechanisms (i.e. basic access mode, request to send/clear to send (RTS/CTS), CTS-to-self). Our quantified results give a selection basis for the operators to quickly select suitable IEEE802.11g physical layers and the different access mechanisms, and accurately predict the data throughput and delay given the specific parameters.2) Research on dynamically reconfigurable RoF network architecture design and key technologies of the MAC layerHigh speed train is the development trend of the future transportation. In order to provide the fast moving train passengers the reliable multimedia services, great efforts have been made to develop RoF network. In this dissertation, a solution to provide access to train passengers by the use of dynamically RoF network equipped with an intelligent MAC protocol has been proposed and intensively investigated. The proposed RoF network architecture can realize dynamically reconfigurable properties of the control unit and the remote access units. The proposed FDM/TDMA based MAC protocol can realize failure detection/recovery, dynamically wavelength allocation to remote access units (RAUs) and the terminals seamless handover. The results show that with the proposed RoF network architecture and the MAC protocol, the failure caused by WDM lasers can be detected and recovery in the control unit, the dynamically wavelength allocation can increase the wavelength resource utilization and the terminals seamless handover is accomplished on the premise that at least one data transmission cycle is finished in the coverage area of the neighbor cells. 3) Research on green RoF network architecture design and key technologies of the MAC layerThe global power consumption has been increasingly concerned in the access networks and reducing the power consumption is becoming an urgent problem. In this dissertation, a solution to reduce the power consumption of RoF network by the use of RoF network power consumption models and the CSA-MAC (Centralized Control Sleep Aware-MAC) protocol has been proposed and intensively investigated. The total power consumption of IF(intermediate frequency)-over-Fiber and RF(radio frequency)-over-Fiber networks based on the proposed power consumption models are analyzed quantitatively. The quantified results provide basis for selecting a suitable RoF network architecture before actual deployment, while maintaining the tradeoff among the number of joint process units, the number of RAUs and the number of antennas. The proposed CSA-MAC protocol can centralized control the work status of antennas with the help of antenna control fields and the four/two times handshake procedures. With the help of proposed sub-space division based indoor wireless propagation model suitable for RoF network architecture, the received signal strength (RSS) based terminals’ localizations have been gotten. According to these terminals’localizations, antennas can be dynamically scheduled, and the radiate power of the antennas can be fully used.