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LTE-M, which is an abbreviated version of LTE-MTC(Machine Type Communication) can be said to have a variety of applications, including a large number of heterogeneous interconnection of large-scale network equipment. One of the most prominent problems is that the machines may have a large amount of access requests in a short time, which can easily lead to network congestion. At present, the contention-based...
A novel dual channel multiple access (DCMA) protocol is proposed for multihop wireless networks to efficiently resolve hidden and exposed terminal problems and improve the probability of concurrent packet transmissions. By optimizing the slots on control channel and data channel, DCMA can achieve optimal transmission balance, and concurrent reservation access and collision-free data packet transmissions...
To improve cooperative efficiency in mobile ad hoc networks, a relay-optimized cooperative MAC (RO-CMAC) protocol is proposed in this paper. In the protocol, an optimal relay is selected through two or three contention phases in case of low data rate of direct transmission from a sender to its recipient. In the first phase, all relays with the highest data rates to the sender and its recipient are...
A new slotted split-channel medium access control (SSC-MAC) protocol is proposed for multihop wireless networks to maximize concurrent packet transmissions. By adjusting the relationship between the reservation slot (RS) on the control channel (CCH), data packet transmission slot (TS) on the data channel (DCH) and acknowledgment slot (AS) on the acknowledgment channel (ACH), the channel reservation,...
In order to eliminate the adverse effects of long propagation delay and ensure the quality-of-service (QoS) of high-priority traffic for long propagation delay networks, a new propagation-delay-tolerate MAC (PDT-MAC) protocol with adaptive reservation is proposed. A novel frame structure is designed to maximize the throughput and avoid packet collisions. A piggyback mechanism is also used to reduce...
The improved partial proportional fair (IPPF) algorithm for OFDMA relay system is proposed, aiming at solving the fairness scheduling problem. Subcarriers are distributed to all users in both two sub-timeslots. And the relay users are regarded as two users in the subcarrier scheduling for the second sub-timeslot, so as to balance the data rates of all users. The IPPF algorithm achieves a better balance...
Long Term Evolution (LTE) and LTE-A researchers are deploying variety of techniques such as Multiple Inputs Multiple Outputs (MIMO) to achieve the higher throughput, while paying little attention to power consumption. In this paper, meticulous base station power consumption model is proposed, while more significantly, the model is calibrated. Then the relations between system parameters and power...
This paper presents a high resolution and frame rate image signal processor (ISP) array design for three-dimensional (3-D) imager. Based on the through-silicon via (TSV) technology, the short connections of the 3-D integrated circuit (IC) can improve the performance and density. Hence, the 3-D imager is the best solution for high throughput image capture or video recorder applications. The proposed...
This paper presents a dual threshold mode switching criteria to optimize the performance of multiple-input multiple-output (MIMO) in Long Term Evolution (LTE) downlink. Transmit diversity (TD) and spatial multiplexing (SM) is the basic MIMO transmission modes in LTE-A standards. General method for mode switching based on Signal-to-Noise-and-Interference Ratio (SINR) or CQI is merely a single threshold...
The performance of traditional TCP congestion control protocol degrades when congestion and contention increase in ad hoc networks that use the IEEE 802.11 DCF. Many of the problems result from medium contention at the media access control (MAC) layer. In this paper, we present a new contention-based congestion control (CBCC) method according to a novel congestion information from MAC layer. This...
In this paper, we present a bit-plane parallel architecture for a modified SPIHT without lists algorithm using the breadth first search for coefficient trees. This scheme can ensure that the quality of reconstructed images is almost the same with that of SPIHT with lists. Compared with the other architectures, our architecture has advantages of high parallelism, no intermediate buffer and ability...
As an essential part of Multi-channel MAC protocol, the channel scheduling algorithm aims at enhancing the network throughput and resource utilization. Based on the WAVE standard in vehicular communications, this paper improves WAVE MAC by using the time division access on service channels and proposes a channel scheduling scheme to negotiate and allocate the channel resources for throughput-sensitive...
This paper presents a distributed adaptive QoS medium access control (DAQ-MAC) protocol for mobile ad hoc networks. The protocol assigns nodes accessing channel in three phases: the prioritization phase, the contention phase and the transmission phase. The prioritizations of data packets are expressed by a few binary signed digits. In the prioritization phase, when binary signed digit is “0”, nodes...
Fast reservation list-to-send (FRLS) medium access control (MAC) protocol is proposed to apply to wireless networks with long propagation delay. In the protocol, a central control node (CCN) is applied to allocate the channel resources of two channels, and all the nodes transmit packets over the two channels without collision. Packet train transmission mechanism ensures that a number of packets are...
In this paper, a collision-free on-demand multiple access (CF-ODMA) protocol for mobile ad hoc networks is proposed. In the CF-ODMA protocol, every node obtains collision-free polling service by channel reservation. In addition, a collision resolution algorithm is presented to guarantee that in the present of reservation collisions the access nodes can successfully access channel in sequence, and...
This paper proposes a RSU assisted multi-channel coordination MAC (RAMC) protocol that fully utilizes all DSRC channels to provide simultaneous safety and non-safety communications. Within the radio range of a roadside unit (RSU), vehicles are free to tune to any service channels. The RSU monitors all the safety messages being transmitted in both the control and service channels. Periodically, the...
A novel cooperative routing protocol, namely throughput-optimized cooperative routing (TOCR) protocol, is proposed to improve network throughput in ad hoc network. Through calculation, we can deduced that by fixed transmission power, a cooperative node can raise received signal to noise ratio (SNR) at the receiving of recipient node, and then increase the probability of successful packets reception...
An upstream congestion control (UCC) protocol based on cross-layer design is proposed to reduce packet losses and energy waste due to a large number of retransmissions and packet drops. The UCC protocol takes advantage of unoccupied buffer size and traffic rate at MAC layer as congestion level indication, and based on which, every upstream traffic rate is adjusted at network layer with its source...
Congestion in wireless sensor networks (WSNs) can lead to packet losses, delay, and energy waste due to a large number of retransmissions and packet drops. It is necessary to carry out congestion control which detects congestion precisely and regulates it fairly. To achieve this objective, an upstream hop-by-hop congestion control (UHCC) protocol based on cross-layer design is proposed. Unlike existing...
The priority method is proposed for wireless LAN in this paper, which is that different workstations are distinguished with different business in wireless LAN, through modeling and simulation, the network performance parameters are analyzed in the priority mechanism, the results showed that the priority mechanism can achieve the better network performance. To a certain extent, it is guaranteed that...
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