Carrier Sense Multiple Access With Collision Detection Research Articles

Supporting Multimedia Services over A Token-Passing Bus Local Area Network.(Dept.E)

Besides data transactions such as web surfing and e-commerce, the Internet today has been experiencing growth in audio and video streaming with the emergence of multimedia tools. However, the existing network infrastructure (e.g., Ethernet) only offers a single best effort class of service without any guarantees on delay variation, packet losses or available bandwidth. This can adversely impact the end-to-end performance of multimedia applications. Accordingly, a different class of Media Access Control (MAC) protocols must be used to support multimedia services over the existing Local Area Networks (LANs) without seeking to ehange it [3]. The token-passing bus was introduced to avoid the non-determinism of Carrier Sense Multiple Access with Collision Detection (CSMA/CD) bus protocol as well as the complexities of active repeaters in the token ring [8]. This makes, token-passing bus MAC protocol is the best candidate to support multimedia traffic over Ethernet LANs [8]. In this paper, the capability of the token-passing bus LANs to provide multimedia services is explored and its performance under different multimedia traffic loads is evaluated using a simulation program.

A Cross-Layer Design for a Multihop, Self-Healing, and Self-Forming Tactical Network

In mission and time critical applications, bandwidth and delay optimizations are the key goals of communication systems. This paper presents a cross-layer framework design that reduces the call setup time, provides collision-free communication, and reuses the empty slots of Time Division Multiple Access (TDMA) protocol which otherwise causes low throughput and large delay. As number of communicating nodes in tactical networks is small as compared to commercial mobile ad hoc networks (MANETs), classical TDMA will yield huge number of empty slots and any Carrier Sense Multiple Access/Collision Detection (CSMA/CD) technique may cause more delay in some critical scenarios. Proposed methodology gives a Cross-Layer Architecture for Network (NET) Layer and Medium Access Control (MAC) Layer. Our design provides bandwidth efficient, collision-free communication to Software-Defined Radios (SDRs) in self-forming and self-healing tactical networks with low call setup time and multihop routing. For this purpose TDMA as MAC layer protocol and Ad Hoc On Demand Distance Vector (AODV) as Network Layer Routing Protocol are used. Our slot allocation (SA) algorithm, Cross-Layer TDMA (CL-TDMA), consists of control phase where AODV control packets are exchanged and data transfer phase where transmission of data and voice occurs. All active radios in vicinity gather information about communicating nodes based on the exchange of control packets by SDRs. Our algorithm then uses this information to help all active SDRs find slot(s) that will be used for collision-free transmission. A number of experiments are performed to establish improved performance of the proposed technique compared to other established techniques and protocols.

Performance evaluation of embedded ethernet and Controller Area Network (CAN) in real time control communication system

<span lang="EN-US">Real-time communication is important in control network. In real-time communication, message need to be delivered from source to destination within specification. Embedded Ethernet and Controller Area Network (CAN) protocol can be used in control network to achieve hard real-time communication. For embedded Ethernet protocol, Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is the media access control (MAC) used to control data transmission between nodes in network. Back-off algorithm in CSMA/CD is used to handle packet collisions and retransmission. For CAN protocol, it is communication protocol developed mainly for automotive application. It has priority arbitration to handle collisions and retransmission. In this project, embedded Ethernet network models and CAN network models are developed and simulated in MATLAB Simulink software. Several back-off algorithms, which are Binary Exponential Backoff (BEB), Linear Back-off Algorithm, Exponential-Linear back-off Algorithm and Logarithm Back-off Algorithm are proposed and implemented into Embedded Ethernet network model to evaluate the performance. Both embedded Ethernet and CAN network models are extended to 3 nodes, 10 nodes, and 15 nodes to evaluate performance at different network condition. The performance criteria evaluated and discussed are average delay and jitter of packets. The results show that in network with high number of nodes, Linear Back-off Algorithm and Exponential-Linear back-off Algorithm shows improvement in packets delay and jitter. For CAN network, the packet jitter is relatively low.</span>

Efficient 3-D Bus Architectures for Inductive-Coupling ThruChip Interfaces

Wireless 3-D network-on-chips (NoCs) with inductive-coupling ThruChip interfaces provide a large degree of flexibility for customizing the number of arbitrary chips in a package after chips have been fabricated. To simplify the vertical communication interfaces, static time division multiple access (TDMA) is used for the vertical broadcast buses, while arbitrary or customized topologies can be used for the intrachip network. This paper proposes two techniques to break through the simple static TDMA-based vertical buses while maintaining a simple communication interface. The first technique is headfirst sliding (HS) routing to reduce the waiting time for acquiring the communication time-slot. HS routing selects the best vertical bus based on the current time, taking advantage of static TDMA. The second technique extends carrier sense multiple access with collision detection (CSMA/CD) for vertical broadcast buses. We introduce a packet collision detection technique for inductive-coupling buses and propose two retransmission strategies to reduce the waiting time for packet retransmissions caused by collisions. Network simulation results show that HS routing reduces the communication latency by 39.1% compared with the conventional static TDMA bus-based 3-D NoC that uses the shortest path routing. The proposed CSMA/CD bus also improves the latency by 52.5% and throughput by 34.1%. The full-system simulation results show that HS routing and the proposed CSMA/CD technique reduce the application execution time accordingly while maintaining the average flit transfer energy overhead modest.

CSMA/CN: Carrier Sense Multiple Access With Collision Notification

A wireless transmitter learns of a packet loss and infers collision only after completing the entire transmission. If the transmitter could detect the collision early [such as with carrier sense multiple access with collision detection (CSMA/CD) in wired networks], it could immediately abort its transmission, freeing the channel for useful communication. There are two main hurdles to realize CSMA/CD in wireless networks. First, a wireless transmitter cannot simultaneously transmit and listen for a collision. Second, any channel activity around the transmitter may not be an indicator of collision at the receiver. This paper attempts to approximate CSMA/CD in wireless networks with a novel scheme called CSMA/CN (collision notification). Under CSMA/CN, the receiver uses PHY-layer information to detect a collision and immediately notifies the transmitter. The collision notification consists of a unique signature, sent on the same channel as the data. The transmitter employs a listener antenna and performs signature correlation to discern this notification. Once discerned, the transmitter immediately aborts the transmission. We show that the notification signature can be reliably detected at the listener antenna, even in the presence of a strong self-interference from the transmit antenna. A prototype testbed of 10 USRP/GNU Radios demonstrates the feasibility and effectiveness of CSMA/CN.

Probabilistic Model Checking of the CSMA/CD Protocol Using PRISM and APMC

Carrier Sense Multiple Access/Collision Detection (CSMA/CD) is the protocol for carrier transmission access in Ethernet networks (international standard IEEE 802.3). On Ethernet, any Network Interface Card (NIC) can try to send a packet in a channel at any time. If another NIC tries to send a packet at the same time, a collision is said to occur and the packets are discarded. The CSMA/CD protocol was designed to avoid this problem, more precisely to allow a NIC to send its packet without collision. This is done by way of a randomized exponential backoff process. In this paper, we analyse the correctness of the CSMA/CD protocol, using techniques from probabilistic model checking and approximate probabilistic model checking. The tools that we use are PRISM and APMC. Moreover, we provide a quantitative analysis of some CSMA/CD properties.

Making real-time Ethernet a reality

Current Ethernet standards promise transfer speeds of 100Megabits and more. This is significantly faster than established most of the field bus systems, and embedded network. Therefore Ethernet also seems to be a good choice for connecting industrial devices with real time requirements. With Ethernet, data communication can be delayed unpredictably. The reason for Ethernet's nondeterminism is its stochastic media access mechanism CSMA/CD (carrier sense multiple access with collision detection). To achieve predictable timing on Ethernet network collision need to be avoided. Moving from shared Ethernet to a switched Ethernet seems to be a promising solution. Time slicing is a better method for predictable data communication via Ethernet with very short cycle times and precise timing.

Switch based industrial Ethernet networks

When Ethernet was first invented by Dr Robert Metcalfe in the mid-1970s, communication at the physical layer was based on coaxial cables. Steadily increasing technical demands in terms of data rates and network topologies have fuelled a continuous evolution in the physics of data transfer. Today it is the shielded twisted pair (STP) which is the preferred transmission medium. However, the access procedure which regulates the exchange of data over these lines, i.e. the procedure which defines how data stimulates the transmission medium, remains the same: CSMA/CD (carrier sense multiple access with collision detection). When the need arises at an Ethernet node to exchange data - to send an e-mail, for example - the Ethernet controller checks whether there is already data traffic on the line (Carrier Sense, CS). If the check proves negative, the node begins the transmission sequence. During this sequence, the node continuously monitors whether another Ethernet station has begun a data transmission during this timeframe which might cause data to collide and be destroyed.

Comparative dynamic performance of token passing and CSMA/CD LANs for a flexible manufacturing system

This paper presents a methodology for investigating the dynamic performance of a local area network (LAN) using token passing and carrier-sense multiple access with collision detection (CSMA/CD) communication protocols for a flexible printed circuit boards assembly (PCBA) system. It has been implemented by formulating an integrated model, in which both an operational system's function and an information processing system's function are modelled and simulated in order comprehensively to predict system behaviour and to obtain an optimal solution that maximizes systems performance. The relevant impact on logical interactions and interrelationships between operations and information processing systems within the manufacturing environment has been quantified. The research has shown that this approach may provide a useful basis for developing existing modelling frameworks and a practical means of exploring existing modelling simulation methodologies. In principle, this technique is valuable for analysing a wide range of manufacturing systems.

Equilibrium point analysis of the binary exponential backoff algorithm

A Markovian model of the backoff algorithm used in the slotted 1-persistent carrier sense multiple access/collision detection (CSMA/CD) access protocol is developed in order to analyze the performance of such a network. Due to its complexity, the existing models of the CSMA/CD protocol do not incorporate the effects of the backoff algorithm. In this work, we developed an approximate Markovian model of the system with a multidimensional state vector and we used the equilibrium point analysis technique in order to analyze the model. The throughput–delay characteristics and the stability behavior of the system are extracted, which conform the simulation results and the predictions of other theoretical models presented in the literature.

Scheduling Messages with Earliest Deadline Techniques

This paper discusses the applicability of earliest deadline scheduling techniques to local area networks. The focus is on controller area networks (the only standard that allows direct implementation) although a comparison is tried with other possible implementations on different network topologies (and contention resolution methods). Message scheduling follows the well-known EDF algorithm. The paper discusses the limitations and the problems in the implementation of the algorithm on standard controller area network protocols. Then, it presents a short study on the comparative effectiveness of other contention resolution methods modeled on the standards Token-ring and Carrier Sense Multiple Access-Collision Detection CSMA-CD (all implementing the earliest deadline scheduling policy.) Finally, the paper shows how to compute an optimal packet size with respect to the guaranteeability of the real-time properties, exploiting the trade-off between preemptability and efficiency.

CSMA with reservations by interruptions (CSMA/RI): a novel approach to reduce collisions in CSMA/CD

This paper proposes an enhancement for the carrier sense multiple access with collision detection (CSMA/CD) protocol, called CSMA with reservations by interruptions (CSMA/RI). This new protocol uses a novel approach to reserve capacity by interrupting an ongoing packet transmission. The performance of the protocol is studied by simulations under realistic (long range dependent) traffic conditions and compared to the CSMA/CD, token ring protocols, as well as with the work conserving G/D/1 queue. It is demonstrated that CSMA/RI always offers better performance than CSMA/CD, and under certain realistic assumptions regarding packet size, the performance of CSMA/RI can be very close to that of token-ring and G/D/1.

A Production-Efficiency Oriented Approach for Evaluating The Performance of a Local Area Network

Network technology plays a vital role in integrating manufacturing facilities and controlling production information flows. A computer-integrated manufacturing (CIM) system with different production characteristics, e.g., production throughput rate and the amount of process infonnation, should be facilitated with a network protocol that meets the individual CIM system's requirements. PEO-NET, a Production-Efficiency-Oriented Network Evaluation Tool, is developed in this paper which adopts network efficiency (Esys), an improved practical perfonnance evaluation index, as the decision criteria while determining the installation suitability of the tentative network protocol. In order to achieve greater portability and flexibility, PEO-NET is designed with three replaceable modules: 1) the CIM system configuration module for defining the configuration of a CIM system as well as its production requirements, 2) the industrial network protocol simulation module for predicting the production communication behavior under different network protocols, and 3) the network perfonnance analysis module for generating the network efficiency significance decision table. Simulations are also perfonned to demonstrate how PEO-NET is facilitated as a decision support tool for selecting a feasible network protocol for both job shop and flow shop production environment with two major LAN (Local Area Network) protocols: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) and Token Passing Bus, respectively.

Ｅｔｈｅｒ型ネットワークにおける動画像伝送に関する研究

The recent remarkable advances in information systems require that networks satisfy the demands of multimedia transmission. 100Base-T is a high-speed extended version of 10Base-T and is being introduced extensively. In this paper, we are concerned with the performance of standard 100Base-T networks and 100Base-T networks that have been modified for the integrated transmission of motion picture and computer data. The modified 100Base-T is one of a number of 1-persistent CSMA/CD (Carrier Sense Multiple Access with Collision Detection) systems which can reduce both the expectation and variance of transmission delays. We evaluate the performance of both CSMA/CD systems and discuss the improvement obtained by the modified system.

Translucent smart pixel array (TRANSPAR) chips for high throughput networks and SIMD signal processing

We present a novel architecture for an optical network, translucent smart pixel array (TRANSPAR), having smart pixel devices which effectively function in an optically translucent manner. The network protocol is similar to carrier-sense multiple-access/collision-detection (CSMA/CD) commonly used in Ethernet, but adapted to a ring configuration using optical parallel packets in free space. The TRANSPAR devices also function as a fine-grain mesh-connected parallel pipeline array for image and video signal processing. We designed, fabricated, and are currently testing the TRANSPAR smart pixel devices and network node hardware. This paper presents the network architecture, tradeoffs, and design decisions, the testing results to date, and ends with considerations on practicality and future scalability.

Capacity of the AMPS reverse control channel

We evaluate the capacity of the reverse control channel (ReCC) common to both the advanced mobile phone systems (AMPS) (TIA-553) and time-division multiple-access (TDMA) (IS-54) cellular standards. These two standards currently account for approximately 35 million cellular customers in North America. The random-access protocol employed is a variant of carrier-sense multiple-access/collision detection (CSMA/CD), which makes use of a busy/idle bit on the forward control channel (FoCC) for both carrier sensing and collision detection. We describe this random-access protocol in detail, obtain the ReCC throughput characteristic analytically, and show that capture has a negligible impact on the maximum ReCC throughput. The analytic result correctly predicts the maximum attainable throughput, but does not reflect ReCC features such as the maximum number of retries, which were designed to stabilize the random-access protocol. A detailed simulation study of the ReCC complements the analytic study and shows the throughput and access delay that can practically be obtained.

Queueing analysis of a hybrid CSMA/CD and BTMA protocol with capture

A performance study of the access channel of a mobile, micro-cellular radio telephone network is presented. The access method used is a combination of the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) and the Busy Tone Multiple Access (BTMA) protocols with modified access and back-off probabilities. Based on an imperfect channel and the likely low connectivity of the mobiles with the base station, two new, semi-Markov renewal models are constructed; the asynchronous time, infinite population model, and the synchronous time, finite population model. The latter uses the mini-slot property of the channel, and it is proven to have a matrix geometric representation. The analysis assumes that capture is due either to slow Rayleigh fading or to power level variations with the distances, and the corresponding capture probabilities are calculated analytically, or by using standard Monte Carlo simulation techniques. With the proposed hybrid protocol applied to both models when the capture is perfect, the performance is similar to the classic CSMA/CD, and thus it is better than the performance obtained by the ALOHA or CSMA algorithms with capture. Nevertheless, the power capture effect does not offer a similar improvement in the maximum achieved throughput, as in the cases of the ALOHA or CSMA contention based protocols. But, if capture due solely to slow fading is present, our hybrid model has considerably better performance than the corresponding CSMA (α = 0.01) and BTMA protocols. However, with the proposed algorithm the channel shows a bi-stable behaviour, unless the offered traffic is extremely low. The analysis allowed us to draw some very useful conclusions for both models developed. Thus, in the case of the synchronous time, finite population model and with respect to the throughput-delay performance, the most important parameters, including the attempt rate, the signal-to-noise ratio and the length of the successful and unsuccessful messages, are considered. For suitable parameter values, and independently of the attempt rate, the channel appears to have an acceptable operational point. In the case of the infinite model, interest has been given in real systems with NCFSK and CPSK modulations, operating in a slow Rayleigh fading environment. Note that if only power capture is present, the same model yields an upper bound on the throughput. The analysis shows that the maximum achievable throughput is obtained for the same value of traffic rate, independently of the packet length. Higher values of the average SNR leads the system to approach the nonfading case.

The role of medium access control protocols in SCADA systems

This paper deals with the influence of the medium access control (MAC) protocol in the performance of the communication channels used in power system SCADA systems (supervisory control and data acquisition). Three types of MAC protocols are presented and analyzed: polling, CSMA/CD (carrier sense multiple access with collision detection), and token bus. The simulation of each one of these protocols allows us to quantify its performance and establish certain criteria in order to be able to compare them. As a result of the analysis, the use of a MAC protocol is proposed for SCADA systems.

Network access protocol for hard real-time communication systems

Distributed hard real-time systems are characterized by communication messages associated with timing constraints, typically in the form of deadlines. A message should be received at the destination before its deadline expires. Carrier sense multiple access with collision detection (CSMA/CD) appears to be one of the most common communication network access schemes that can be used in distributed hard real-time systems. In this paper, we propose a new real-time network access protocol which is based on the CSMA/CD scheme. The protocol classifies the messages into two classes as ‘critical’ and ‘noncritical’ messages. The messages close to their deadlines are considered to be critical. A critical message is given the right to access the network by preempting a noncritical message in transmission. Extensive simulation experiments have been conducted to evaluate the performance of the protocol. It is shown that the protocol can provide considerable improvement over the virtual time CSMA/CD protocol proposed for hard real-time communication by Zhao et al. 1.

Modelling and Simulation of the Operational and Information Processing Functions of a Computer-Integrated Manufacturing Cell

This paper investigates the information processing function of a computer-integrated manufacturing (CIM) system, which is usually neglected by engineers when they study the performance of a manufacturing system. The feasibility of developing a complete simulation model which would include both the operational and information processing functions is therefore considered. In order to achieve this, a typical pick-and-place manufacturing cell was considered in which 46 devices were connected to a local area network (LAN). Two independent simulation tools, SIMAN* and L-NET†, were used in order to develop the complete model. The model was evaluated and used to study the performance of the pick-and-place cell using different communication protocols such as the IEEE 802.3 carrier sense multiple access with collision detection (CSMA/CD), IEEE 802.4 token bus and the IEEE 802.5 token ring. Results presented in this paper show that with careful design and simulation it is possible to develop a complete model which includes both operational and informational processing functions. Although the example of the pick-and-place cell is relatively simple the technique adopted could be applied to any CIM system. Results have also shown that for the pick-and-place cell considered in this paper an IEEE 802.3 CSMA/CD protocol operating at 10 Mbps would guarantee access to the network within the shortest station processing time.