Analysis of Quality of Service Assurance in Wireless Networks

This Bachelor thesis deals especially with possibilities of quality of service assurance and mobility implementation in wireless networks. It deals primarily with the possibilities of the IEEE 802.11e standard, with the applicability of the Mobile IPv4 protocol and with the computer simulation of their mutual coactions in the OPNET Modeler 12.0 environment. In the first part of the thesis the standard IEEE 802.11e is first of all analysed from the theoretical point of view. It is followed by the detailed description of the IEEE 802.11e standard, its individual parts and implementation possibilities of advanced technologies of the access to the medium which are included in the standard. In this part even the individual advantages and disadvantages of the original access methods of wireless networks of IEEE 802.11 standards are briefly outlined. Further part of this work deals with the theoretical analysis of mobility service assurance in the IP networks and with the mobility implementation in individual layers of the ISO/OSI models. Then the Mobile IPv4 protocol is presented here that carries out the mobility in the IP networks. The principle of this protocol is mentioned here and its individual components and the network architecture are presented. In the next part, on the basis of theoretical pieces of knowledge in the environment of the OPNET Modeler simulation tool the effect of the standard IEEE 802.11e implementation is examined on the selected statistics of the wireless local network. Furthermore the effect of the load in the network is followed up and standard modifications are discussed here to reach optimum results. The last part deals with the computer simulation of the Mobile IPv4 protocol in the wireless networks. Then the support of the IEEE 802.11e standard is implemented into the functioning network model and the reciprocal coactions of both technologies and a possible appearance of any problems are examined. For comparison, it is here in the OPNET Modeler environment even the mobility simulated which is based solely on the link layer