• ETRI Journal
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• v.28 no.3
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• pp.311-319
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• 2006

This paper presents a terminal-assisted frame-based packet reservation multiple access (TAF-PRMA) protocol, which optimizes random access control between heterogeneous traffic aiming at more efficient voice/data integrated services in dynamic reservation TDMA-based broadband access networks. In order to achieve a differentiated quality-of-service (QoS) guarantee for individual service plus maximal system resource utilization, TAF-PRMA independently controls the random access parameters such as the lengths of the access regions dedicated to respective service traffic and the corresponding permission probabilities, on a frame-by-frame basis. In addition, we have adopted a terminal-assisted random access mechanism where the voice terminal readjusts a global permission probability from the central controller in order to handle the 'fair access' issue resulting from distributed queuing problems inherent in the access network. Our extensive simulation results indicate that TAF-PRMA achieves significant improvements in terms of voice capacity, delay, and fairness over most of the existing medium access control (MAC) schemes for integrated services.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.513-518
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• 2010

This paper proposes a medium access control protocol for integrated voice and data services in slotted CDMA systems. The proposed protocol, which is named as RCSSMA (Reservation Code and Status Sensing Multiple Access), adopts a code reservation and status sensing schemes. RCSSMA protocol gives higher access priority to the voice traffic than data traffic for reducing the packet dropping probability. The voice terminal reserves an available spreading code to transmit voice packets during a talkspurt, whereas the data terminal transmits a packet over one of the available spreading codes that are not reserved by the voice terminals. In this protocol, the voice packets never contend with the data packets. Packet dropping probability and average data packet transmission delay are analyzed using a Markov chain model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3A
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• pp.141-150
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• 2012

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, firstly, a time slot reservation protocol for relay transmission is proposed. Furthermore, we propose a novel relay node selection algorithm adaptive to current UWB link transmission rate. The proposed relay node selection algorithm has compatibility with current WiMedia D-MAC standard and is executed at each device according to the SoQ as a QoS criterion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.692-700
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• 2012

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and Wireless USB. In this paper, firstly, the fair SoQ-based Distributed Reservation Protocol (DRP) for D-MAC is analyzed. And a novel SoQ-based relay transmission protocol is proposed to overcome DRP conflicts fast. In the proposed protocol, each device executes the Satisfaction of QoS (SoQ) time slot allocation algorithm independently. And, in order to give the loser device due to DRP conflicts another chance to maintain QoS resources, the proposed relay transmission protocol helps the device reserve another indirect link maintaining the required QoS resources via a relay node.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.755-761
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• 2013

Medium access control (MAC) protocols for wireless sensor networks make sensor nodes on state for energy-efficiency only when necessary. In this paper we present an energy efficient priority-based MAC protocol for energy-harvesting Wireless Sensor Networks (WSNs). For support priority-based packet transmission the proposed EEPB-MAC protocol uses the modified IEEE 802.15.4 beacon frames including priority bit, sender node address, and NAV value fields. A receiver node periodically wakes up, receives sender beacon frames, selects data sending sender, and broadcasts a beacon frame containing the selected sender's address. A receiver node selects sender node according to sender's data priority. A receiver nodes also adjust wake up period based on their energy states. Hence, the energy consumption of receiver node can be minimized. Through simulations and analytical analysis, we evaluate the performance of our proposed the EEPB-MAC protocol and compare it against the previous MACs. Results have shown that our protocol outperforms other MAC in terms of energy consumption, higher priority packet delivery delay.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.31-34
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• 2002

There are two kinds of network architectures in the IEEE 802.11:[1] distributed (ad-hoc) or centralized (infrastructure) wireless network. Centralized networks have an access point (base station) that can control the wireless medium access of stations in these networks. The 802.11 MAC protocol of an access point is the same as those of other stations in the contention period. This paper propose a novel MAC protocol of an access point to solve these problems. This MAC protocol adds a new contention-free period called EPCF (Extended PCF) to resolve accumulated data in the queue of an access point. Simulation results show that the new protocol performs better throughput than the 802.11 standard MAC with the less queue memory site requirement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1425-1433
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• 1999

In this Paper, we analyzed the HIPERLAN(Hlgh PErformance Radio LAN) MAC(Medium Access Control) protocol, which was a standard for Wireless LANs defined by ETSI. We analyzed mathematically the elimination phase and the yield phase of the channel contention phase of CAC(Channel Access Control) layer in the infinite population model of the HIPERLAN using EY-NPMA(Elimination Yield-Nonpreemptive Priority Multiple Access)protocol. Also we analyzed the probability of successful transmission in the transmission phase. And, we proved results of a mathematical analysis by the simulation of HIPERLAN MAC protocol.

• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.13-24
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• 2005

The sensor network is a key component of the ubiquitous computing system which is expected to be widely utilized in logistics control, environment/disaster control, medical/health-care services, digital home and other applications. Nodes in the sensor network are small-sized and exposed to adverse environments. They are demanded to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes than the wireless ad hoc networks are. In case that some nodes consume up their power capacity, the network topology should change, and rerouting/retransmission is necessitated. Communication protocols studied for conventional wireless networks or ad hoc networks are not suited for the sensor network resultantly. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a medium access protocol to enhance the efficiency of energy consumption in the sensor network node. Its performance is analyzed by simulation.

• Journal of Communications and Networks
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• v.17 no.3
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• pp.247-255
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• 2015

In this paper, we propose an adaptive time division multiple access based medium access control (MAC) protocol, called bitmap-assisted shortest job first based MAC (BS-MAC), for hierarchical wireless sensor networks (WSNs). The main contribution of BS-MAC is that: (a) It uses small size time slots. (b) The number of those time slots is more than the number of member nodes. (c) Shortest job first (SJF) algorithm to schedule time slots. (d) Short node address (1 byte) to identify members nodes. First two contributions of BS-MAC handle adaptive traffic loads of all members in an efficient manner. The SJF algorithm reduces node's job completion time and to minimize the average packet delay of nodes. The short node address reduces the control overhead and makes the proposed scheme an energy efficient. The simulation results verify that the proposed BS-MAC transmits more data with less delay and energy consumption compared to the existing MAC protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2465-2472
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• 2015

Wireless Medium Access Control (MAC) and routing technologies are the basic building blocks making it possible the Internet of Things (IoT). These technologies have been the focus of substantial research in the last decade. Nevertheless, as new networking standards for IoT are being proposed and different solutions are patched together, evaluating the performance of the network becomes unclear. In this paper, a new overview of MAC and routing protocols for IoT and new interactions are given. The IEEE 802.15.4 MAC and Routing Protocol for Low-power Lossy Network (RPL) routing protocols are taken as reference to exemplify and illustrate the discussion. Experimental results show that contention-based access MACs may hurt the routing, unless these two are carefully designed together.