In Ad-hoc wireless network, connectivity is a fundamental issue which restricts the design of system protocol. Based on the theory of stochastic geometry, a connectivity model focused on signal-to-interference （SIR） ratio is set up in presence of Nakagami-m fading and interference. This paper derives a close formula of connectivity probability with interference and Nakagami-m fading which is never obtained in previous works. Two-dimension shot-noise theory in stochastic geometry for interference is well applied. The formula is verified by simulation. The results show that the connectivity is affected by the scatter of users, wireless propagation environment, interference and so on.
One of the key issues for radio resources management is network selection strategy in heterogeneous scenarios. In order to provide ubiquitous service, the paper puts forward a network selection algorithm based on multiple attribute decision making （MADM） and group decision making （GDM）. Firstly, the proposed algorithm acquires attribute weights＇ vectors of the subjective and objective decision makers based on MADM, and then the two attribute weights＇ vectors are synthesized to be a new attribute weights＇ vector by using GDM. Considering that the results of GDM should be reasonable and convincible, the criterion of consistency is adopted for judging the compatibility of group judgments. More specit]cally, the algorithm takes into account not only objective attributes of networks but also the preference of subscribers and traft]c class Hence it guarantees that the subscribers can not select the networks with poor performance depending on their preference. The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide subscribers with satisfactory quality of service （QoS）.
