Aloha-type random-access protocols have been employed as access control protocols in wireline and wireless, stationary and mobile, multiple-access communications networks. They are frequently employed by the control and signaling subsystem of demand-assigned multiple access protocols for regulating the sharing of a control channel. The latter is used for the transport of reservation packets req...

In this paper, we consider a novel ambient backscatter multiple-access system, where a receiver (Rx) simultaneously detects the signals transmitted from an active transmitter (Tx) and a backscatter Tag. Specifically, the information-carrying signal sent by the Tx arrives at the Rx through two wireless channels: the direct channel from the Tx to the Rx, and the backscatter channel from the Tx to...

In this paper, we investigate the network utility maximization problem in energy harvesting cognitive radio sensor networks (CRSNs). Different from traditional sensor networks, sensor nodes in CRSNs are embedded cognitive radio modules, enabling them to dynamically access the licensed channels. Since the dynamic channel access is critical to guarantee the network capacity for CRSNs, existing so...

The popular IEEE 802.11 WLAN today does not provide any quality-of-service (QoS) because of its contention-based channel access nature of the medium access control (MAC). Therefore, we proposed a simple software upgradebased solution, called a dual queue scheme, to provide QoS to real-time services such as Voiceover-IP (VoIP) in our previous work. The dual queue scheme operates on top of the le...

In this paper we consider the problem of distributed throughput maximization of networks with multi-channel ALOHA medium access protocol. In the multi-channel ALOHA protocol, each user tries to randomly access a channel using a probability vector defining the access probability to the various channels. First, we characterize the Nash Equilibrium Points (NEPs) of the network when users solve the...