Evaluation of RFID Anti-Collision Protocols Using Java Based Tool

The importance of Wireless Sensor Network (WSN) increases due to deployment for geographical, environmental and surveillance purpose in war fields. WSN facing several challenges due to its complex nature including key problems, such as routing and medium access control protocols. Several approaches were proposed for the performance evaluation of WSN on the basis of these issues due to the fact that MAC layer access protocols have a great impact on the performance of WSN. In this paper, we investigated the performance evaluation of three well known MAC Access protocols, i.e. sensor medium access control protocol (SMAC), carrier sense multiple access with collision avoidance (CSMA/CA), and time division multiple access (TDMA) over adhoc on demand distance vector (AODV) routing protocol. The number of simulation scenarios were carried out by using NS- 2, the simulation metrics used are throughput, end-to-end delay and energy consumed. Simulation results showed that SMAC out perform CSMA/CA and TDMA by consuming less energy, less end to end delay and high throughput due to contention based approach to access the medium for transmission.

Wireless networks have become a very attractive solution for soft real-time data transport in the industry. For such technologies to carry real-time traffic, reliable bounds on end-to-end communication delays have to be ascertained to warrant a proper system behavior. As for legacy wired embedded and real-time networks, two main wireless multiple access methods can be leveraged: one is time division multiple access (TDMA), which follows a time-triggered paradigm, and the other is carrier sense multiple access with collision avoidance (CSMA/CA), which follows an event-triggered paradigm. This paper proposes an analytical comparison of the time behavior of two representative TDMA and CSMA/CA protocols in terms of the worst-case end-to-end delay. This worst-case delay is expressed in a probabilistic manner because our analytical framework captures the versatility of the wireless medium. Analytical delay bounds are obtained from delay distributions, which are compared to fine-grained simulation results. Exhibited study cases show that TDMA can offer smaller or larger worst-case bounds than CSMA/CA depending on its settings.

Recently, the Wi-Fi alliance announced a new Wi-Fi standard known as IEEE 802.11ah (or Wi-Fi HaLow) to efficiently support Internet of Things (IoT) applications. However, the existing registration method under IEEE 802.11ah, based on carrier-sense multiple access with collision avoidance (CSMA/CA), was analyzed as not efficient enough for registration of large-scale machine-to-machine (M2M) communications where a massive number of devices try to access a single, centralized access point (AP). In this paper, we propose a hybrid slotted-CSMA/CA–time-division multiple access (TDMA) (HSCT) medium access control (MAC) protocol for efficient massive registration of IoT devices (up to 8000) in M2M networks. We focus on situations, where a large number of M2M devices simultaneously try to register at a single, centralized AP. In the proposed HSCT, contention-based slotted-CSMA/CA allows devices to send an authentication request via randomly selected backoff slots, whereas contention-free TDMA permits those devices to send/receive the subsequent association request/association response via an individually allocated TDMA slot. In addition, a centralized authentication control (CAC)-based mechanism with modified algorithms for optimal selection of CAC parameters and the slotted fixed-window CSMA protocol with Sift geometric probability distribution are used to mitigate severe contention between massive registrations upon network (re-)initialization from an AP reboot. This paper also analyzes the performance of the proposed scheme and determines the optimal configuration to enhance registration performance. Simulation results demonstrate that the proposed HSCT MAC protocol achieves substantial improvement, compared with the contention-free transmission, a combined authentication/association scheme, and the conventional IEEE 802.11ah with CSMA/CA.

WBAN을 위한 MAC 프로토콜은 의료용 센서 노드의 가변적인 데이터를 효율적으로 처리하기 위해서 응급상황에서 발생하는 트래픽을 가장 높은 우선순위로 처리하는 CSMA/CA(: Carrier Sense Multiple Access with Collision Avoidance) 알고리즘을 수행하게 된다. 노드가 전송하는 응급 메시지는 충돌이 발생하게 되고 응급 메시지 재전송으로 인한 전송 지연이 발생할 수 있으며 재전송으로 인한 에너지 낭비를 가져올 수 있다. 본 논문에서는 이러한 문제점들을 개선하기 위해서 우선순위 큐잉을 적용한 CSMA/CA 알고리즘의 경우 MAC 명령어 프레임과 데이터 프레임의 우선순위를 정하여 서로 다른 백오프 파라미터를 적용하고 충돌로 인한 프레임 손실을 최소화하는 알고리즘을 제안하였다. 성능평가 결과 제안한 MAC 프로토콜을 사용했을 때가 IEEE 802.15.6을 사용했을때 보다 충돌 확률이 감소하여 패킷 전송 처리율이 증가하고 패킷 손실량이 감소함을 보였다. MAC protocol for WBAN performs CSMA/CA(:Carrier Sense Multiple Access with Collision Avoidance)algorithm that handles traffic which occurs in emergency with top priority in order to deal with variable data of sensor node for medicine. Emergency message that node sends undergoes collision and delay of transmission by retransmission of emergency message and waste of energy by retransmission. This paper suggests algorithm that minimizes loss of frame caused by collision and applies different backoff parameters by setting order of priority between MAC instruction frame and data frame in CSMA/CA algorithm case which applies order of priority queuing to improve aforementioned problem. According to performance evaluation, it has been found that using suggested MAC protocol showed lower collision probability, higher packet transmission processing ratio and lower packet loss compared with using IEEE 802.15.6.

An airdropped meteorological parameters measurement network (AMPMN) is introduced in this paper. AMPMN with star topology is composed of two kinds of nodes, sensor nodes and one relay node, all equipped with nRF905 radio frequency (RF) modules. A three-layer protocol is built on nRF905 in terms of its configuration. The RF configuration parameters and the payloads formats are set to enable the implementation of carrier sense multiple access with collision avoidance (CSMA/CA) or time division multiple access (TDMA) schemes through programming. The performances of two presented CSMA/CA schemes and one designed TDMA scheme are evaluated by simulation. Based on the simulation results and the difficulty of practical implementation, the CSMA/CA scheme without RTS/CTS is selected for AMPMN. AMPMN will be used in unmanned meteorological parameters measuring over hazard area.

In this paper we present a two-dimensional medium access control (MAC) protocol. Orthogonal frequency division multiple access (OFDMA) can make multiple stations (STA) transmit simultaneously on different sub-channels. On the other hand, carrier sense multiple access with collision avoidance (CSMA/CA) could make different stations contend the available channel from the time domain to avoid collision with each other. We propose a two-dimensional MAC protocol based on OFDMA and CSMA/CA in broadband systems. With the new designed MAC protocol different stations will access the channel from the time-frequency domain without interference and collision. The combination of OFDMA with CSMA/CA will improve the system throughput with efficient MAC and decrease the collision probability. We design that different stations will contend the available time-frequency resources dynamically under fairness. The system throughput of the designed protocol is analyzed and simulation results are presented to show the performance under our designed protocol far better than the conventional CSMA/CA protocol.

A vehicular ad hoc network (VANET) is designed to enable efficient and authentic node/infrastructure communication. The primary role of VANETs is to distribute time-sensitive safety messages (sm) regularly, which causes packet congestion and broadcast failure due to the network’s limited spectrum. For efficient and reliable delivery, the proposed paper uses a spatial hybrid division multiple access (SDMA) and time division multiple access (TDMA) over the control channel interval and hence termed a spatially distributed multichannel MAC (SDM-MAC) protocol. The frequency reuse approach is used to transfer data while efficiently utilising bandwidth, and throughput is considerably enhanced with carrier sense multiple access with collision avoidance (CSMA/CA) and with the help of TDMA. Moreover, an adaptive algorithm is proposed for an intelligent channel frame structure using this protocol to manage the highly dynamic scenario. The Markov chain defines the protocol, and the network simulator (NS2) analyses several performance metrics. Comparing the response with two existing MAC protocols, the proposed protocol reduces average latency compared to current MAC methods and improves the packet delivery ratio and throughput by an average of 26% and 28%, respectively.

Power consumption, latency, and complexity are considered to be a benchmark for comparing Medium Access Control (MAC) protocols in Wireless Sensor Networks (WSN). However, the importance of these elements varies according to the application. In this paper, three MAC protocols are proposed for forest fire detection. Basically, two of these protocols are based on the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol with some modification to suit the forest fire detection application. These protocols are called Persistent CSMA (P-CSMA) and Per Hope Synchronization CSMA (PHS-CSMA). The third one is a Time Division Multiple Access (TDMA)-based protocol, called Sensor TDMA (S-TDMA). These three protocols are investigated and analyzed by simulation. Results show that there is no superior protocol which outperforms others in terms of power consumption, delay and complexity. However, a trade-off does exist. In terms of power consumption, S-TDMA outperforms other protocols but it has the worst performance in terms of delay. On the other hand, considering the design complexity, S-TDMA is the most complex as it needs time synchronization over the entire cluster while PCSMA and PHS-CSMA don't require time synchronization between nodes.

The IEEE 802.15.3c/mmWave WPAN has been recently proposed as one of the most promising technologies that can allow broadband access in future 5G mobile networks. In this standard, the carrier sense multiple access with collision avoidance (CSMA/CA) technique was adopted to allow medium sharing between mobile devices co-located in the same small-cell. The performances of this access technique depend on two main parameters, the carrier sense threshold and the contention window derived from the persistence probability. One of the major limits of this method is that it can lead extensive contention and thus limited throughput. In this paper, we investigate the design of a contention based multiple access control technique for 5G wireless access networks where the carrier sense threshold and the persistence probability are dynamically adjusted according to the observed contention level observed by the device on the network. To this end, we model the multiple access paradigm in 5G networks using a non-cooperative game-theoretic framework, and we show that it admits an equilibrium. In addition, we propose a fully distributed multiple access control CSMA/CA based algorithm where the carrier sense threshold and the persistence probability are intelligently tuned according to the collision level gathered by the device on the shared wireless medium until reaching the equilibrium state. Through the simulations, we demonstrate that the proposed game theoretic based CSMA/CA outperforms the original version of the algorithm in terms of success transmission rate and delay.

The current stage of telecommunication technologies development is characterized by the rapid growth use of wireless technologies in access networks and the growth requirements for its quality. The bottleneck that significantly reduces the bandwidth of each subscriber connection is that the total bandwidth of the wireless local network is shared among its active members by the shared technology used. The access management sub-layer to the shared physical environment is responsible for this in the network architecture. The main method used at this sub-layer is the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme. This work is devoted to the analysis of CSMA/CA scheme and the development of an analytical model for its further study and use for the improvement of wireless local networks. The input data is a transition state diagram of a local area wireless network station in data transmission mode. According to the CSMA/CA scheme, stations cannot change their state after starting frame transmission until a confirmation frame of successful reception arrives from the addressee or until the time to wait for it expires. Considering this, it is proposed to use a simplified transition state diagram for the analysis. The operation of the station by the simplified transition state diagram is described using a system of differential equations. As a result of the solution of this system, expressions representing the probability of the station being in each of its states as a function of the intensities of the station’s transitions from each state to another are derived. The values of these intensities depend on both the outgoing traffic of the station and the traffic in the network. The resulting expressions can be used in further work on the analysis of the CSMA/CA scheme, as they make it possible to estimate the operation of the station at different ratios of the station’s output traffic and external traffic generated by other stations of the network. This can be used to develop an enhanced algorithm station operation of wireless local area networks by adapting the parameters of the CSMA/CA scheme to specific current loads of both the station and the network.

The effectiveness of wireless local area networks significantly depends on the method of access to the common physical environment. The main access method that is used today in wireless local area networks is carrier sense multiple access with collision avoidance (CSMA/CA), managing the efficient distribution of the common environment between active stations. In this paper, as a topic of research we consider the state transition diagram of a CSMA/CA - based network, and we describe it by a system of differential equations. Analytical expressions for the probabilities of being in one of the possible states of a network station are derived.KeywordsWireless local computer networkCarrier sense multiple access with collision avoidance (CSMA/CA)State transition diagram

3rd generation partnership project (3GPP) has developed 5-GHz unlicensed band long term evolution (LTE), referred to as licensed-assisted access (LAA). LAA adopts listen-before-talk (LBT) operation, resembling Wi-Fi's carrier sense multiple access with collision avoidance (CSMA/CA), to enable collision avoidance capability. However, the frame structure overhead of each LAA downlink burst varies with the ending time of each preceding LBT operation. Given that, the existing analytic models of Wi-Fi cannot be used to evaluate the performance of LAA due to the fact that, unlike Wi-Fi, LAA frame structure overhead varies with the ending time of the preceding LBT operation. In this letter, we propose a novel Markov chain-based analytic model to cope with the variation of the LAA frame structure overhead. Comparison between analysis and simulation results shows that the difference between them is merely 0.2% on average, demonstrating the accuracy of the proposed model.

As a promising approach to the rendezvous problem in cognitive radio networks (CRNs), a blind rendezvous paradigm has recently spawned various asynchronous channel-hopping (CH) rendezvous schemes that enable any two neighboring secondary users to meet among multiple channels within a finite time, even with no synchronization. However, the rendezvous delay that was derived in existing work is unable to reflect the actual channel access delay performance in multiuser CRNs, as it only relies on hopping patterns of the elaborately designed CH sequences (CHSs) and ignores the impact of network factors (e.g., channel availability and multiuser contention). In this paper, channel access delay is investigated by jointly considering asynchronous CH rendezvous schemes, channel availability, and a medium-access control (MAC) protocol in a single-hop multiuser CRN. To coordinate multiuser contention, a carrier sense multiple access with collision avoidance (CSMA/CA) MAC is adopted by tailoring the IEEE 802.11 distributed coordination function (DCF) properly to the operation features of existing asynchronous CH rendezvous schemes. The channel access delay is analyzed based on a modified Bianchi model and an absorbing Markov chain model, which captures the aggregate effect of hopping patterns of CHSs, the dynamic nature of channel availability, and the behavior of the MAC protocol. The analytical results are verified through extensive simulations. Both simulation and analytical results reveal that the rendezvous delay in existing asynchronous CH rendezvous schemes is insufficient to ensure satisfactory channel access delay in multiuser CRNs.

In this paper, we advocate implementing carrier sense multiple access with collision detection (CSMA/CD) in the broadband power line communication (BB-PLC) standard, G.hn, and show the gain in data rate obtained over carrier sense multiple access with collision avoidance (CSMA/CA). The use of CSMA/CD is made feasible due to the recent implementation of in-band full duplex operation in BB-PLC. We provide this implementation on a G.hn model using the NS-3 simulator, which we have made available as open-source. Our G.hn model implements physical and data link layers, including repeating function that makes it possible to simulate the long line network topologies (e.g., the network for electricity metering purpose). We also add IP/UDP layers to accomplish the higher layer protocol stack. We also provide analytical calculations of efficiency gains and validate them through our simulation results. We show that the highest achievable data rate with CSMA/CD is up to 5% higher than with CSMA/CA. Furthermore, we demonstrate that the protocol with CSMA/CD is less dependent on the number of active senders and has a smaller range of optimal contention window sizes (CW) for the same range of active senders, in comparison to CSMA/CA. This also simplifies the protocol implementation as the back-off algorithm for CSMA/CD does not vary CW as much as for CSMA/CA.

IEEE 802.15.4 employs a medium access control protocol based on carrier sense multiple access with collision avoidance (CSMA/CA). Channel sensing may have critical impact on the system throughput and energy consumption as well. In this paper, we investigate the effect of channel sensing on the CSMA/CA performance in IEEE 802.15.4 star-topology configured networks. We show that the hidden node ratio (i.e., the probability that any two child nodes cannot hear each other in a star-topology configured network) is highly associated with the target false-alarm probability of the channel sensing detector. We show that the CSMA/CA performance of IEEE 802.15.4 network can significantly be improved by adjusting the hidden node ratio.