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This paper analyzes the impact and benefits of directional antennas in improving the throughput scaling law of a large wireless network in an information-theoretic perspective. More specifically, we deal with a general scenario where the beamwidth of each node can scale at an arbitrary rate relative to the number of nodes in the network. We then introduce an elastic routing protocol, which enables...
This paper presents a solution for improving the network spectral efficiency (NSE) of a MIMO ad hoc network by simultaneously increasing the number of concurrent links in the network while maximizing the spectral efficiency of each. Our approach combines multiple physical layer techniques and balances the trade-offs of them. Assuming only the channel state information to the intended receiver, a two-level...
This paper proposes a MAC protocol using multiple control channels for multi-channel ad-hoc network. In the proposed protocol, all channels are divided into some groups. Each group has a control channel. All nodes hops the control channels for searching a receiver. Because of using multiple control-channels, control frame collisions and the effect of searching overhead are mitigated in the proposed...
In ad hoc networks, radio interference and terminal' mobility can cause frame losses. When the frame losses occur continuously, general datalink layer protocols regard it as a link failure and then notify it to network layer protocols. In conventional routing protocols, a source terminal initiates route discovery process to recover from the link failures on receiving the notifications even if the...
Multicasting is intended for group communication, which supports the dissemination of information from a sender to all the receivers in a group. Mobile wireless Ad Hoc networks are infrastructure less and often used to operate under unattended mode, posing problems like scarcity of bandwidth, short lifetime of the nodes due to power constraints, and dynamic topology caused by the mobility of nodes...
In this study, we enhance achievable sum-rate in an ad hoc network consisting of two source-destination pairs and k half-duplex Decode-and-Forward (DF) relays. We assume that two receivers use strong interference cancellation technique and can cancel strong interference. Then, in order to enhance the achievable sum-rate, we propose a novel relay selection scheme that can make Strong and Weak Interference...
Interconnecting consumer electronic devices in an ad-hoc manner is considered one of the solutions to provide next generation services like “Ambient Intelligence” or the “Internet of Things”. Since the transmission range of a single device is limited, multi-hop techniques are often employed to provide a larger network coverage. In such a mobile ad-hoc network (MANET) broadcast data is often disseminated...
Since the seminal work of Grossglauser and Tse [1], the two-hop relay algorithm and its variants have been attractive for mobile ad hoc networks (MANETs) due to their simplicity and efficiency. However, most literature assumed an infinite buffer size for each node, which is obviously not applicable to a realistic MANET. In this paper, we focus on the exact throughput capacity study of two-hop relay...
We consider a wireless network with transmitters and receivers sharing a common channel. We study the maximum link activation (LA) problem under a novel setup, where the transmitters are able to cooperatively transmit data and the receivers have interference cancellation (IC) capabilities. In this version of LA problem, determining which transmitters should jointly transmit and to whom, as well as...
Connectionless multicast protocols are well suited for networks with a large number of small multicast groups. These protocols however do not scale with large groups, and are not robust for high mobility. We proposed a connectionless multicast protocol named MCOM that addresses the issues of mobility, scalability, and robustness. The MCOM protocol design allows for better scalability by group size...
Cellular network operators usually have to maintain networks of different generations (2G, 3G, 4G, …) simultaneously. The progressive upgrade of users' terminals makes the spectrum of the legacy networks become gradually underused. An operator can enable cognitive radio techniques at its newest generation terminals to reuse the spectrum of its own legacy networks. We propose an hybrid access scheme...
A novel multichannel MAC protocol called time slotted channel reservation based MAC protocol (TSCR-MAC) for cognitive radio networks is introduced, specified, illustrated and simulated. TSCR-MAC demands only one half-duplex CR radio and employs common control channel for information exchange. In TSCR-MAC a time slot is assigned a separate frequency channel. It allows a pair of communicating nodes...
In this paper, we consider an implementation of approximate decoding algorithm that enables receivers to recover source data from insufficient number of network coded symbols. We reevaluate several theoretical properties of approximate decoding algorithms in the perspective of actual implementation over TCP/IP and we quantify the impact of packet sizes and the sizes of finite field on the performance...
Ad-hoc networks are becoming an effective tool for many mission critical applications such as troop coordination in a combat field, situational awareness, etc. These applications are characterized by the hostile environment that they serve in and by the multicast-style of communication traffic. Therefore, authenticating the source and ensuring the integrity of the message traffic become a fundamental...
In this paper, we will propose a Cooperative Power and Contention control MAC (CPC-MAC) protocol in Cognitive Radio Ad Hoc Networks to solve the multichannel hidden terminal Primary User (PU) problem by build appropriate number of monitor nodes in suitable positions. There are two functions in this mechanism. First, secondary user (SU) transmitter sends the RTS frame including transmission power to...
The paper analyses the outage probability of a radio node in a finite size large-scale data aggregation network which employs slotted random medium access. In most literature, this performance metric is usually derived from a Poisson point process distribution of radio nodes in infinite space. In contrast, we analyse a network with finite area and a fixed number of interfering nodes using a binomial...
In wireless ad-hoc networks where concurrent transmissions of data messages by hidden wireless nodes should be avoided, better trade off between reliability and transmission delay is required. The authors have proposed the method to adaptively apply either BEC (Backward Error Correction) or FEC (Forward Error Correction) based on bit error ratio and transmission request frequence. In FEC communication,...
To reduce the difficulties in calculating the aggregated interference power at an observed receiver, a Power Emission Density-based analysis method is proposed in this paper. By utilizing the new method, the traditional discrete-style calculation (i.e., obtain each concurrent interferer's impact on the observed receiver individually, and add them together) can be replaced with a concise integration...
In this paper, we consider the use of an electric-supplied coordinator exploiting much higher transmission power than battery-supplied nodes in low power and lossy networks (LLNs). Since the coordinator can transmit via one hop instead of multiple hops over downlink, it is possible to reduce the communication overhead significantly. To take this advantage, we propose a single hop downlink protocol...
The performance of Wireless Ad hoc Networks (WANETs) depends on the availability of Channel State Information (CSI) on all channels in the network. In this work we study the performance when each receiver has CSI only on the channel from its desired transmitter. We present a novel lower bound on the Ergodic Rate Density of a WANET with partial CSI. The novel bound is compared to a previously known...
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