There are several technologies for providing broadband services over wireless and cellular networks. The fundamental one in the evolution from 3G to 4G is probably the High Speed Downlink Packet Access (HSPA) technology. There are many works in the literature tackling the problem of HSPA performance and capacity. Most of the developed techniques involving HSPA capacity are related to the system...

Despite significant research effort, the performance of distributed medium access control methods has failed to meet theoretical expectations. This paper proposes a protocol named “Channel MAC” performing a fully distributed medium access control based on opportunistic communication principles. In this protocol, nodes access the channel when the channel quality increases beyond a threshold, whi...

In this paper, we derive a capacity region for Gaussian fading multiple access degraded relay channel with partial channel state information (CSI) at the transmitters (CSIT) and perfect CSI at the receiver (CSIR). The achievable rate region obtained by Kramer-Wijngaarden is a special case of our region. Keywords-Gaussian fading channel; channel state information (CSI); discrete multiple access ...

In this paper, new two-user multiple access wiretap channel models are studied. First, the multiple access wiretap channel II with a discrete memoryless main channel, under three different wiretapping scenarios, is introduced. The wiretapper, as in the classical wiretap channel II model, chooses a fixedlength subset of the channel uses on which she obtains noise-free observations of one of the ...

Densely deployed WiFi networks will play a crucial role in providing the capacity for next generation mobile internet. However, due to increasing interference, overlapped channels in WiFi networks and throughput efficiency degradation, densely deployed WiFi networks is not a guarantee to obtain higher throughput. An emergent challenge is how to efficiently utilize scarce spectrum resources, by ...