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Wireless Networks
Published in Vikas Kumar Jha, Bishwajeet Pandey, Ciro Rodriguez Rodriguez, Network Evolution and Applications, 2023
Vikas Kumar Jha, Bishwajeet Pandey, Ciro Rodriguez Rodriguez
Layer 2 of the OSI model is the data link layer that specifies the way to access devices, share the transmission media, and ensure the reliability of physical connection. The two important mechanisms under the data link layer are MAC and logical link control. The wired network has an important feature of collision detection part of Carrier Sense Multiple Access/Collision Detection (CSMA/CD) under the MAC sublayer that is not possible for radio access wireless networks. For the wireless networks, a variant of CSMA/CD known as CSMA/collision avoidance is used where collision detection is not possible. CSMA/collision avoidance has some similarities with CSMA/CD apart from no collision detection by the transmitting device, which is the devices can sense the medium before transmission of the packet and can wait if the medium is busy. Protocol standards for the wireless networks are Wi-Fi (IEEE 802.11), Bluetooth (IEEE 802.15.1), and so on.
Fundamentals of Internet of Things
Published in Bhawana Rudra, Anshul Verma, Shekhar Verma, Bhanu Shrestha, Futuristic Research Trends and Applications of Internet of Things, 2022
Sarthak Srivastava, Anshul Verma, Pradeepika Verma
Bluetooth is one of the most commonly known wireless communication protocols, working on data link layer of TCP/IP network model and communication layer of IoT network architecture, used to connect two devices for one-to-one communication for data exchange and to build the personal area networks (PANs) in short-range using short wavelength UFH radio waves (2.4 to 2.485 GHz). Bluetooth 5 is the latest version of this communication protocol, with about 800% more data broadcasting frequency compared to its earlier version and it’s four times longer range and doubled speed make it a very smart choice for the IoT systems. Low power consumption, cheaper cost, fast and secured connection, and low interference characteristics make it a very prominent device to be used for wireless networks [34] (Figure 1.9).
Security in Wireless Sensor Networks
Published in Shafiullah Khan, Al-Sakib Khan Pathan, Nabil Ali Alrajeh, Wireless Sensor Networks, 2016
The link layer is responsible for multiplexing of data streams, data frame detection, medium access control, and error control [1]. Attacks at this layer include purposefully created collisions, resource exhaustion, and unfairness in allocation. A collision occurs when two nodes attempt to transmit simultaneously on the same frequency [29]. When packets collide, they are discarded and need to be retransmitted. An adversary may strategically cause collisions in specific packets such as ACK control messages. A possible result of such collisions is the costly exponential backoff. The adversary may simply violate the communication protocol and continuously transmit messages in an attempt to generate collisions. Repeated collisions can also be used by an attacker to cause resource exhaustion [29]. For example, a naive link layer implementation may continuously attempt to retransmit the corrupted packets. Unless these retransmissions are detected early, the energy levels of the nodes would be exhausted quickly. Unfairness is a weak form of DoS attack [29]. An attacker may cause unfairness by intermittently using the aforementioned link layer attacks. In this case, the adversary causes degradation of real-time applications running on other nodes by intermittently disrupting their frame transmissions.
TCN enhanced novel malicious traffic detection for IoT devices
Published in Connection Science, 2022
Liu Xin, Liu Ziang, Zhang Yingli, Zhang Wenqiang, Lv Dong, Zhou Qingguo
Ethernet Data Frame Header: At the data link layer, the data carrier is an Ethernet data frame. Ethernet has different versions of the protocol. We use Ethernet II here, which is defined in IEEE 802.3x (IEEE, n.d.). The address information can be used as the identity information of the data stream to be temporarily stored.IPv4 Packet Header: As the definition in RFC791 (Postel, 1981b), all fields are stored as feature information in this paper.TCP Header: We use the TCP protocol as the target protocol, which is defined in the RFC793 document (Postel, 1981a). “Flag,” “Window Size”, “Urgent Pointer,” and “Options” fields are temporarily stored as features, and “Source Port” and “Destination Port” are temporarily stored for identification.
Analysis of time delays in scheduled and unscheduled communication used in process automation
Published in Automatika, 2020
S. M. A. K. Azad, K. Srinivasan
Foundation Fieldbus (FF) is one of the leading communication protocol used for remote control in industrial process automation. FF is a digital and multi-drop communication that supports interoperability where FF devices are operated remotely. Transmitter or actuator with a control unit embedded in it is called a smart device, used to control the process remotely [26]. The FF communication protocol is similar to the OSI model with four layers out of which, data link layer (DLL) plays a vital role in accessing the data. The configuration of Foundation Fieldbus devices and their medium access satisfies IEC61158 standards. FF is a communication channel between the DeviceNet and Host system (Control System) for measuring the process value of multiple control loops connected in the network for a specified time slot [27]. The typical architecture of the communication network for FF is as shown in Figure 1.
Adaptive load distribution approach based on congestion control scheme in ad-hoc networks
Published in International Journal of Electronics, 2019
Varun Kumar Sharma, Mahesh Kumar
Figure 4 illustrates the modules included in the proposed method, the MAC parameter module (MAC-PM): the subject is used to identify currently available routes with a preferred channel and load conditions. MAC-PM is updated by the frame transmission module (FTM) and queue status module (QSM) at internet layer with the help of cross-layer module (CLM). FTM calculates the total number of MAC level retransmission and transmission efficiency for a packet ‘P’ as shown in Equations (1), (2), (3), (7) and (9). QSM, which is integrated in data link layer, estimates the current unused proportion of queue for a node as shown in Equations (4), (5), and (11). Further, the proposed method also classifies and analyses the numerous reasons for a packet loss in wireless systems. The packet losses may be either due to channel interference, wireless channel characteristics, a high error rate present in the channel, or buffer-overflow. İn this article, we discover about the aforementioned packet dropping events which influence our system performance at the data link layer.