Data-link Protocol Research Articles

A Survey on Time-Sensitive Networking Standards and Applications for Intelligent Driving

Stimulated by the increase in user demands and the development of intelligent driving, the automotive industry is pursuing high-bandwidth techniques, low-cost network deployment and deterministic data transmission. Time-sensitive networking (TSN) based on Ethernet provides a possible solution to these targets, which is arousing extensive attention from both academia and industry. We review TSN-related academic research papers published by major academic publishers and analyze research trends in TSN. This paper provides an up-to-date comprehensive survey of TSN-related standards, from the perspective of the physical layer, data link layer, network layer and protocol test. Then we classify intelligent driving products with TSN characteristics. With the consideration of more of the latest specified TSN protocols, we further analyze the minimum complete set of specifications and give the corresponding demo setup for the realization of TSN on automobiles. Open issues to be solved and trends of TSN are identified and analyzed, followed by possible solutions. Therefore, this paper can be an investigating basis and reference of TSN, especially for the TSN on automotive applications.

Aircraft Mode S Transponder Fingerprinting for Intrusion Detection

Nowadays, aircraft safety is based on different systems and four of them share the same data-link protocol: Secondary Surveillance Radar, Automatic Dependent Surveillance System, Traffic Collision Avoidance System, and Traffic Information System use the Mode S protocol to send and receive information. This protocol does not provide any kind of authentication, making some of these applications vulnerable to cyberattacks. In this paper, an intrusion detection mechanism based on transmitter Radio Frequency (RF) fingerprinting is proposed to distinguish between legitimate messages and fake ones. The proposed transmitter signature is described and an intrusion detection algorithm is developed and evaluated in case of different intrusion configurations, also with the use of real recorded data. The results show that it is possible to detect the presence of fake messages with a high probability of detection and very low probability of false alarm.

Control and Readout Software for Superconducting Quantum Computing

Being important parts of the superconducting quantum computer, the high-speed arbitrary waveform generator (AWG), ultraprecision dc source, and high-speed digitizer are used to manipulate the qubit. The complexity of an experimental setup increases rapidly as the number of qubits grows. Cumbersome instrument management, distortion of signals, and inefficiency of data transmission are gradually highlighted and become the bottlenecks in scaling up the number of qubits. In addition, fault-tolerant quantum computing has real-time feedback requirements of qubit states. To deal with these challenges, we propose an instrument management software design in this paper. The software maps the resources of separate instruments to a unified virtual instrument, achieving the scalability of the instruments. The processing and correction of signals are deployed on a server, which automatically corrects the distortion of the signals. By designing a multi-threaded mechanism for the AWG and a custom-defined data-link protocol for the digitizer, the efficiency of the software meets the requirements of experiments. Cooperating with the AWG and digitizer, the software provides the real-time feedback capability using an instruction compiler. Thus, the software meets the requirements of superconducting quantum computing, as demonstrated through its application to a 12-bit quantum experiment.

A Study on Network Operation Structure and DataLink Protocol for Interworking of Ground Network ALL-IP at Next-Military Satellite Communication

A Study on Network Operation Structure and DataLink Protocol for Interworking of Ground Network ALL-IP at Next-Military Satellite Communication

AGV Controlled FMS

One of the key factors that prevent the implementation of Flexible Manufacturing Systems (FMS) is the elaborate cost associated with the control software. In a FMS there is often a wide range of equipment, such as personal computers, Programmable Logical Controllers (PLCs), CNC Machines or robots, each of these having their ownintelligence' and library of data. Providing a means of communication between these individual controllers has traditionally been achieved using a Local Area Network (LAN). This proves more expensive when traditional manual operated machines have to be integrated into the system. The model described in this paper provides an alternative to the con- ventional use of a LAN in a FMS environment. In the design solution, an Automatically Guided Vehicle (AGV) is used as both the materials handling unit and the communications line linking each station to the host controller. Communications between the AGV and peripheral equipment is achieved using a standard infrared data link, eliminating hard-wiring and network protocols. A simulation model has been developed to demonstrate the feasibility of such a system, using industrial data. The software package Witness is used to develop the simulation model. The objective from developing this simulation model is to test whether an AGV is capable of meeting the demands of such a scenario. The research undertaken aims to test this by modelling an existing factory layout. Using this layout and captured machining times and part routes, from the factory database, the feasibility of such AGV controlled production system is established. The model shows that such a system is plausible in a scenario where machine times are high and the distance between machines is large.

IMPORTANCE OF SLIDING WINDOW PROTOCOL

The data can get lost, reordered or duplicated due to the presence of routers and buffer space over th e unreliable channel in the conventional networks. The data link layer deals wi th frame formation, flow control, error control, an d addressing and link management. All such functions will be performed on ly by data link protocols. The sliding window proto col will detect and correct error if the received data have enough redundant bi ts or repeat a retransmission of data. The paper sh ows the working of this duplex protocol of data link network.

Self-Stabilization with r-Operators revisited

We present a generic distributed algorithm for solving silents tasks such as shortest path calculus, depth-first-search tree construction, best reliable transmitters, in directed networks where communication may be only unidirectional. Our solution is written for the asynchronous message passing communication model, and tolerates multiple kinds of failures (transient and intermittent). First, our algorithm is self-stabilizing, so that it recovers correct behavior after finite time starting from an arbitrary global state caused by a transient fault. Second, it tolerates fair message loss, finite message duplication, and arbitrary message reordering, during both the stabilizing phase and the stabilized phase. This second property is most interesting since, in the context of unidirectional networks, there exist no self-stabilizing reliable data-link protocol. The correctness proof subsumes previous proofs for solutions in the simpler reliable shared memory communication model.

On the use of rate and power adaptation in V-BLAST systems for data protocol performance improvement

In this paper we address the issue of optimizing the performance of data-link and transport protocols running on a system including multiple transmit and receive antennas with a V-BLAST architecture. More specifically, we explore the possibility of adaptively selecting which transmit antennas and which per antenna rates to use as well as the antenna transmit powers in order to maximize the rate of data packets successfully delivered through the system. This is a novel approach with respect to the recent literature which is generally focused on channel capacity optimization. We show that the use of this rate/power adaptation technique, when a data transmission protocol is running over the link, may lead to significant throughput improvements especially at small signal-to-noise ratios.

Packet dropping statistics of a data-link protocol for wireless local communications

We consider a data transmission system over a wireless channel, where packets are queued at the transmitter. Automatic repeat request is employed as the error control scheme, by which packets corrupted due to channel impairments are immediately retransmitted. We study the statistics of the packet dropping process due to buffer overflow. In particular, we propose a Markov approximation to model such losses. The delay performance of the packets that are admitted to the queue is studied, and extensions of the analysis to general nonindependent arrival processes are also presented.

A simple data link protocol for high-speed packet networks

Many popular point-to-point data link protocols use the high-level data link control (HDLC) framing mechanism, which delineates protocol data units (PDUs) by means of a special bit pattern or flag. When such a flag occurs in the payload portion of a frame, an escape byte used to pad the transmitted byte stream enables the receiver to differentiate between a true framing flag and an occurrence of the flag pattern in the user information. The need to process each byte in the incoming byte stream to identify the flag pattern makes this frame delineation method increasingly more complex and expensive to implement as the interface speed increases. In addition, the byte stuffing operation performed when the flag pattern appears in the user information stream expands the carried traffic, interfering with quality of service (QoS) management procedures and making the link susceptible to malicious attacks. These factors limit the scalability and QoS management capabilities of the flag-based data link protocols, particularly at high link rates. The increasing popularity of the packet over SONET (POS) protocol stack makes it desirable to find alternative framing protocols. In this paper, we present a simple data link (SDL) protocol. Based on using a Length Indicator field and a header cyclic redundancy check (CRC), rather than a flag, to delineate frames, SDL is inherently scalable to high speeds and provides constant transmission overhead. We discuss the error control, delineation, and resynchronization mechanisms used by SDL, and we describe a link scrambler designed to protect against malicious attacks that attempt to generate very low bit transition density on the line. We also present additional link control functions designed to make SDL suitable for next-generation multiservice networks.

Design and implementation of a QoS oriented data-link control protocol for CBR traffic in wireless ATM networks

This paper presents a QoS oriented Data Link Control (DLC) framework for transporting Constant Bit Rate (CBR) traffic over wireless ATM links. Data link control is usually omitted in fixed ATM networks because cell corruption due to channel error is extremely rare for reliable media like copper wire and optical fiber. However, for wireless, higher bit error rates are quite common due to shadowing and other fading effects. The purpose of DLC in wireless is to provide error-free transport to the higher layers by recovering corrupted cells at the link layer. A selective reject (SREJ) automatic repeat request (ARQ) based DLC protocol is used for CBR error recovery. For an ARQ based scheme, higher recovery rates can be achieved with larger cell transfer delay, caused by cell retransmissions. Since cell transfer delay and DLC recovery rate both translate to user-perceivable Quality-of-Service (QoS), it is important for the DLC to strike a balance between these two, depending on the application's requirements. To achieve this in our protocol, the retransmission procedure for a CBR cell is constrained to complete within a recovery time interval which is specified by the application at call-setup time. Also, a novel jitter removal scheme that reduces the cell delay variation caused by cell loss and retransmissions, is incorporated as a part of the DLC protocol. The proposed protocol is implemented on NEC's WATMnet prototype system. The implementation and its experimental results are reported for illustrating the performance and feasibility of the presented CBR DLC protocol. The experimental results show that the DLC protocol can be successfully applied for QoS-constrained error recovery of CBR traffic on a per-connection basis. These also indicate that the DLC can be programmed to attain a desirable tradeoff between cell transfer delay and cell recovery rate.

AGV controlled FMS

One of the key factors that prevent the implementation of Flexible Manufacturing Systems (FMS) is the elaborate cost associated with the control software. In a FMS there is often a wide range of equipment, such as personal computers, Programmable Logical Controllers (PLCs), CNC Machines or robots, each of these having their own 'intelligence' and library of data. Providing a means of communication between these individual controllers has traditionally been achieved using a Local Area Network (LAN). This proves more expensive when traditional manual operated machines have to be integrated into the system. The model described in this paper provides an alternative to the conventional use of a LAN in a FMS environment. In the design solution, an Automatically Guided Vehicle (AGV) is used as both the materials handling unit and the communications line linking each station to the host controller. Communications between the AGV and peripheral equipment is achieved using a standard infrared data link, eliminating hard-wiring and network protocols. A simulation model has been developed to demonstrate the feasibility of such a system, using industrial data. The software package Witness is used to develop the simulation model. The objective from developing this simulation model is to test whether an AGV is capable of meeting the demands of such a scenario. The research undertaken aims to test this by modelling an existing factory layout. Using this layout and captured machining times and part routes, from the factory database, the feasibility of such AGV controlled production system is established. The model shows that such a system is plausible in a scenario where machine times are high and the distance between machines is large.

The fault span of crash failures

A crashing network protocol is an asynchronous protocol whose memory does not survive crashes. We show that a crashing network protocol that works over unreliable links can be driven to arbitrary global states, where each node is in a state reached in some (possibly different) execution, and each link has an arbitrary mixture of packets sent in (possibly different) executions. Our theorem considerably generalizes an earlier result, due to Fekete et al., which states that there is no correct crashing Data Link Protocol. For example, we prove that there is no correct crashing protocol for token passing and for many other resource allocation protocols such as k -exclusion, and the drinking and dining philosophers problems. We further characterize the reachable states caused by crash failures using reliable non-FIFO and reliable FIFO links. We show that with reliable non-FIFO links any acyclic subset of nodes and links can be driven to arbitrary states. We show that with reliable FIFO links, only nodes can be driven to arbitrary states. Overall, we show a strict hierarchy in terms of the set of states reachable by crash failures in the three link models.

Specification and performance analysis of embedded systems with coloured petri nets

To analyze synchronization, concurrency, communication protocols and system performance, a system level specification is modelled in a coloured Petri net. A toolbox collects information for the implementation, e.g., processing times, waiting times, idle times, data accesses, processing requests. This is illustrated with a data-link protocol system, where the disturbance on the communication channels is modelled, too.

Dlpsim: a teaching harness for data link protocols

Protocol test harnesses have been in use for a number of years to assist implementers in checking conformance of their implementations with reference implementations. The system described here is designed for teaching the principles of data link protocols. Students write protocol implementations in a high-level language and exercise them on a simulator. The simulator checks that data is not duplicated or lost by the protocol. On suitable terminals, visualization of the transmitting window and of the frames traversing the link can provide useful feedback to students. Simple estimates of throughput are also calculated.

PAT: A protocol analysis tutor

A computer-aided learning package, PAT (protocol analysis tutor), developed as a tool to help students and novice data communications engineers learn the basic concepts of data link protocols, is described. The tool enables users to construct the frames of the HDLC (high-level data link control) standard data-link level protocol. The frames can be combined in sequence to form a call, representing the execution of the protocol. At all stages, checks of both the syntax and semantics of the call are made.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The intractability of bounded protocols for on-line sequence transmission over non-FIFO channels

The efficiency of data-link protocols for reliable transmission of a sequence of messages over non-FIFO physical channels is discussed. The transmission has to be on-line; i.e., a message cannot be accessed by the transmitting station before the preceding message has been received. Three resources are considered: The number of packets that have to be sent, the number of headers, and the amount of space required by the protocol. Three lower bounds are proved. First, the space required by any protocol for delivering n messages that uses less than n headers cannot be bounded by any function of n . Second, the number of packets that have to be sent by any protocol that uses a fixed number of headers in order to deliver a message is linear in the number of packets that are delayed on the channel at the time the message is sent. Finally, the notion of a probabilistic physical channel, in which a packet can be delayed on the channel with probability q , is introduced. An exponential lower bound, with overwhelming probability, is proved on the number of packets that have to be sent by any data-link protocol using a fixed number of headers when it is implemented over a probabilistic physical channel.

Analysis of transport measurements over a local area network

Measurements of the end-of-end delay and maximum throughput are reported for a typical implementation of the bottom four layers of the Open Systems Interconnection (OSI) protocols. These comprise the transport, network, data link, and physical protocols. An overview of the four protocols is given, and the experimental environment is described. The measurement results are discussed, and some of the implementation factors that affect the performance of OSI protocols are identified. >

Tree-Based Broadcasting in Multihop Radio Networks

This paper considers the issue of broadcasting protocols in multihop radio networks. The objective of a broadcasting protocol is to deliver the broadcasted message to all network nodes. To efficiently achieve this objective the broad- casting protocol in this paper utilizes two basic properties of the multihop radio network. One is the broadcast nature of the radio which allows every single trasmission to reach all nodes that are in line of sight and within range of the transmitting node. The other, spatial reuse of the radio channel, which due to the multihop nature of the network allows multiple simultaneous transmissions to be received correctly. The proposed protocol incorporates these properties to obtain a collision free forwarding of the broadcasted message on a tree. Centralized and distributed algorithms for the tree construction are presented. The obtained trees are unique in incorporating radio oriented time ordering as part of their definition. In this way multiple copies of one or more broadcasted messages can be transmitted simultaneously without collision, requiring only a small number of message transmissions. Consequently, the protocol not only guarantees that the broadcasted message reaches all network nodes in bounded time, but also ensures that the broadcasting activity will use only limited channel bandwidth and node memory. The proposed broadcast protocol thus possesses the advantages of TDM solutions while allowing the channel bandwidth to be shared, concurrently with the broadcast, with other transmission activities as dictated, for instance, by data link protocols. Some NP-completeness proofs are also given.

Verification of flow control protocols

An important issue in computer network design is end-to-end control, a term covering error control and flow control. The validity of schemes for these purposes may be demonstrated using simple formal models, in which assertions about central program variables are proven. S. Krogdahl [2] and D. E. Knuth [1] have shown the validity of error control for a class of data link protocols using such methods. In this paper their method is extended to cover flow control. The method is illustrated by proving assertions for a simple case, and it is shown how complex systems may be seen as compositions of the simple case.