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Buffer Management in Delay-Tolerant Networks
Published in Khaleel Ahmad, Nur Izura Udzir, Ganesh Chandra Deka, Opportunistic Networks, 2018
The concept of traffic differentiation has been widely used on the Internet to distinguish between different types of traffic that are generated by different application sources and that have different quality of service (QoS) requirements in the network. It allows the network to distinguish packets on the basis of their priority class and favor higher priority class messages over others. Differentiated services (DiffServ) and integrated services (IntServ) are two commonly used techniques on the Internet (Wikipedia). While DiffServ classifies traffic on the basis of their class of service (CoS), giving preferential treatment to higher priority traffic class packets so as to meet their QoS requirement, the best effort model gives equal priority to all types of application data generated in the network and hence is unable to meet the QoS requirements of different applications.
Switched Ethernet in Automation
Published in Richard Zurawski, Industrial Communication Technology Handbook, 2017
Gunnar Prytz, Per Christian Juel, Rahil Hussain, Tor Skeie
QoS on Ethernet is referring to methods to prioritize traffic through the network to reduce latency and jitter for certain types of traffic, that is, to ensure that high priority packets are not delayed by lower-priority packets queued up in a switch [7]. The IEEE 802.1Q [8] Class of Service (CoS) mechanism allows traffic prioritization on Layer 2 Ethernet. There are eight priority levels, 0–7: 7—highest priority (network control, e.g., RSTP packets)…1—lowest priority (background)0—default priority (best effort)
Multiprotocol Label Switching
Published in Goff Hill, The Cable and Telecommunications Professionals' Reference, 2012
DiffServ was proposed in RFC 2475 as a scalable alternative to IntServ. Rather than using a fine-grained signaling of resources, as used in IntServ, DiffServ marks packets with a broad class of service. As IP packet definitions did not originally contain a DiffServ field, DiffServ architects chose to redefine the rarely used IP type of service field and use 6 bits for the DiffServ Code Point (DSCP), as specified in RFC 2474. Each DSCP is mapped to a unique class of service that routers should observe through a predefined Per-Hop Behavior (PHB) for each class. The 6-bit DCSP allows for 26 = 64 possible classes. However, in practice there are three commonly defined classes: Default PHB, which is essentially conventional, best-effort IP forwardingExpedited forwarding for low-latency and low-loss applications such as VoIPAssured forwarding, which uses 12 different DSCPs (four subclasses, each with three different priorities) to give a more flexible PHB (see RFC 2597 for a full explanation)
Packet Scheduling Algorithm in LTE/LTE-Advanced-based Cellular Networks
Published in IETE Technical Review, 2018
The wireless infrastructure of future telecommunication networks will be IP packet based which is also the case for 4G and 5G CNs. The telecommunication users demand high-quality and high-definition display devices, and therefore utilize high DR services from the service providers. Due to the ever increasing traffic base of the users, these CNs are prone to congestion and need a mechanism to prevent large packet losses (PLs) and to incorporate quality of service (QoS). QoS can be incorporated by classification of traffic in terms of real or non-real time services, prioritizing the traffic in terms of class of service (CoS) and origin of traffic generation in the network, and ensuring high-priority traffic is not dropped during congestion scenarios. To this end, a packet scheduling algorithm (PSA) is proposed in this paper which assigns weights to each connection request for every wireless node in the LTE-based CN (LCN). The incorporation of the proposed PSA will ensure lower PL in the CN.