The impact of storage capacity on end-to-end delay in time varying networks

2011 ◽  
Author(s):  
George Iosifidis ◽  
Iordanis Koutsopoulos ◽  
Georgios Smaragdakis
Keyword(s):  
Storage Capacity ◽  
Time Varying ◽  
End To End Delay ◽  
Time Varying Networks ◽  
End To End ◽  
The Impact

Simulated Performance of SCTP and TFRC Over MANETs

2020 ◽  
Vol 16 (2) ◽  
pp. 69-83
Author(s):  
Ali H. Wheeb ◽  
Dimitris N. Kanellopoulos
Keyword(s):  
Multimedia Streaming ◽  
Traffic Load ◽  
Delivery Ratio ◽  
Transmission Protocol ◽  
Streaming Applications ◽  
Simulated Performance ◽  
End To End Delay ◽  
End To End ◽  
The Impact ◽  
Better Than

Mobile ad-hoc networks (MANETs) are composed of mobile nodes communicating through wireless medium, without any fixed centralized infrastructure. Providing quality of service (QoS) support to multimedia streaming applications over MANETs is vital. This paper focuses on QoS support, provided by the stream control transmission protocol (SCTP) and the TCP-friendly rate control (TFRC) protocol to multimedia streaming applications over MANETs. In this study, three QoS parameters were considered jointly: (1) packet delivery ratio (PDR), (2) end-to-end delay, (3) and throughput. Specifically, the authors analyzed and compared the simulated performance of the SCTP and TFRC transport protocols for delivering multimedia streaming over MANETs. Two simulation scenarios were conducted to study the impact of traffic load and node speed (mobility) to their performance. Based on the simulation results, the authors found that the PDR and the end-to-end delay of TFRC are slightly better than those of SCTP in both scenarios. Additionally, the performance of SCTP is significantly better than TFRC in terms of throughput.

scholarly journals Impact of Direction Parameter in Performance of Modified AODV in VANET

2020 ◽  
Vol 9 (3) ◽  
pp. 40 ◽  
Author(s):  
Afsana Ahamed ◽  
Hamid Vakilzadian
Keyword(s):  
Routing Protocol ◽  
Packet Loss ◽  
Routing Protocols ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
End To End Delay ◽  
Distance Vector ◽  
End To End ◽  
Route Request ◽  
The Impact

A vehicular ad hoc network (VANET) is a technology in which moving cars are used as routers (nodes) to establish a reliable mobile communication network among the vehicles. Some of the drawbacks of the routing protocol, Ad hoc On-Demand Distance Vector (AODV), associated with VANETs are the end-to-end delay and packet loss. We modified the AODV routing protocols to reduce the number of route request (RREQ) and route reply (RREP) messages by adding direction parameters and two-step filtering. The two-step filtering process reduces the number of RREQ and RREP packets, reduces the packet overhead, and helps to select the stable route. In this study, we show the impact of the direction parameter in reducing the end-to-end delay and the packet loss in AODV. The simulation results show a 1.4% reduction in packet loss, an 11% reduction in the end-to-end delay, and an increase in throughput.

scholarly journals Evaluating the Impact of Transmission Range on the Performance of VANET

2016 ◽  
Vol 6 (2) ◽  
pp. 800 ◽  
Author(s):  
Akram A. Almohammedi ◽  
Nor K. Noordin ◽  
Sabri Saeed
Keyword(s):  
Traffic Safety ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Traffic Density ◽  
Transmission Range ◽  
Delivery Ratio ◽  
Node Mobility ◽  
End To End Delay ◽  
End To End ◽  
The Impact

Recently, interest in the field of Vehicular Ad-hoc Networks (VANETs) has grown among research community to improve traffic safety and efficiency on the roads. Despite the many advantages, the transmission range in vehicular network remains one of the major challenges due to the unique characteristics of VANETs such as various communication environments, highly dynamic topology, high node mobility and traffic density. The network would suffer from a broadcast-storm in high vehicular density when a fixed transmission range in VANET is used, while in sparse vehicular density the network could be disconnected frequently. In this paper, we evaluated the impact of different transmission ranges and number of flows formed between vehicles in a highway scenario using AODV as routing protocol. In order to validate the simulation of VANET, traffic and network simulators (SUMO & NS-2) have been used. The performance was evaluated in terms of packet delivery ratio and end-to-end delay. The simulation results have shown that better performance was achieved in term of higher PDR and lower end-to-end delay for less than 500 meters transmission range. On the contrary, the PDR started to decrease and end-to-end delay increased when the transmission range exceeded 500 meters. The performance degraded as the number of flows increased.

scholarly journals Exposing End-to-End Delay in Software-Defined Networking

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ting Zhang ◽  
Bin Liu
Keyword(s):  
Large Scale ◽  
Packet Delay ◽  
Software Defined Networking ◽  
Area Network ◽  
Delay Model ◽  
Wide Area Network ◽  
Worst Case ◽  
End To End Delay ◽  
End To End ◽  
The Impact

Software-Defined Networking (SDN) shows us a promising picture to deploy the demanding services in a fast and cost-effective way. Till now, most SDN use cases are deployed in enterprise/campus networks and data center networks. However, when applying SDN to the large-scale networks, such as Wide Area Network (WAN), the end-to-end delay of packet traversal is suspected to be very large and needs to be further investigated. Moreover, stringent time constraint is the cornerstone for real-time applications in SDN. Understanding the packet delay in SDN-based large networks is crucial for the proper design of switch architecture and the optimization of network algorithms such as flow control algorithms. In this paper, we present a thorough systematic exploration on the end-to-end delay in SDN which consists of multiple nodes, fully exposing the components which contribute to the long delay. We disclose that SDN switches cannot completely avoid the generation of flow setup even in proactive mode and conduct data mining on the probability of flow setup. We propose an analytical model for the end-to-end delay. This model takes into account the impact of the different rule installation time consumption on different switches. Considering the delay in switches contributes a large proportion to the entire delay, we conduct various measurements on the delay of a single switch. Results for the delay at different flow setup rates and with different rule priority patterns are presented. Furthermore, we study the impact on packet delay caused by ternary content addressable memory (TCAM) update. We measure parameters in the delay model and find that if SDN is deployed in all segments of WAN, the delay of packet traversal will be increased up to 27.95 times in the worst case in our experimental settings, compared with the delay in conventional network. Such high delay may eventually lead the end-to-end connections fail to complete if no additional measures are taken.

scholarly journals SAI: Safety Application Identifier Algorithm at MAC Layer for Vehicular Safety Message Dissemination Over LTE VANET Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Shuja Ansari ◽  
Marvin Sánchez ◽  
Tuleen Boutaleb ◽  
Sinan Sinanovic ◽  
Carlos Gamio ◽  
...  
Keyword(s):  
Multipath Fading ◽  
System Level ◽  
Mac Layer ◽  
Medium Access ◽  
Safety Message ◽  
End To End Delay ◽  
End To End ◽  
Safety Application ◽  
Application Requirements ◽  
The Impact

Vehicular safety applications have much significance in preventing road accidents and fatalities. Among others, cellular networks have been under investigation for the procurement of these applications subject to stringent requirements for latency, transmission parameters, and successful delivery of messages. Earlier contributions have studied utilization of Long-Term Evolution (LTE) under single cell, Friis radio, or simplified higher layer. In this paper, we study the utilization of LTE under multicell and multipath fading environment and introduce the use of adaptive awareness range. Then, we propose an algorithm that uses the concept of quality of service (QoS) class identifiers (QCIs) along with dynamic adaptive awareness range. Furthermore, we investigate the impact of background traffic on the proposed algorithm. Finally, we utilize medium access control (MAC) layer elements in order to fulfill vehicular application requirements through extensive system-level simulations. The results show that, by using an awareness range of up to 250 m, the LTE system is capable of fulfilling the safety application requirements for up to 10 beacons/s with 150 vehicles in an area of 2 × 2 km2. The urban vehicular radio environment has a significant impact and decreases the probability for end-to-end delay to be ≤100 ms from 93%–97% to 76%–78% compared to the Friis radio environment. The proposed algorithm reduces the amount of vehicular application traffic from 21 Mbps to 13 Mbps, while improving the probability of end-to-end delay being ≤100 ms by 20%. Lastly, use of MAC layer control elements brings the processing of messages towards the edge of network increasing capacity of the system by about 50%.

scholarly journals Timely Reliability Analysis of Virtual Machines Considering Migration and Recovery in an Edge Server

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 93
Author(s):  
Kangkai Liu ◽  
Linhan Guo ◽  
Yu Wang ◽  
Xianyu Chen
Keyword(s):  
Virtual Machines ◽  
First Passage Time ◽  
Passage Time ◽  
Edge Computing ◽  
Delay Constraint ◽  
Vm Migration ◽  
Delay Sensitive ◽  
End To End Delay ◽  
End To End ◽  
The Impact

For the edge computing network, whether the end-to-end delay satisfies the delay constraint of the task is critical, especially for delay-sensitive tasks. Virtual machine (VM) migration improves the robustness of the network, whereas it also causes service downtime and increases the end-to-end delay. To study the influence of failure, migration, and recovery of VMs, we define three states for the VMs in an edge server and build a continuous-time Markov chain (CTMC). Then, we develop a matrix-geometric method and a first passage time method to obtain the VMs timely reliability (VTR) and the end-to-end timely reliability (ETR). The numerical results are verified by simulation based on OMNeT++. Results show that VTR is a monotonic function of the migration rate and the number of VMs. However, in some cases, the increase in task VMs (TVMs) may conversely decrease VTR, since more TVMs also brings about more failures in a given time. Moreover, we find that there is a trade-off between TVMs and backup VMs (BVMs) when the total number of VMs is limited. Our findings may shed light on understanding the impact of VM migration on end-to-end delay and designing a more reliable edge computing network for delay-sensitive applications.

scholarly journals Evaluating the Impact of Transmission Range on the Performance of VANET

2016 ◽  
Vol 6 (2) ◽  
pp. 800
Author(s):  
Akram A. Almohammedi ◽  
Nor K. Noordin ◽  
Sabri Saeed
Keyword(s):  
Traffic Safety ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Traffic Density ◽  
Transmission Range ◽  
Delivery Ratio ◽  
Node Mobility ◽  
End To End Delay ◽  
End To End ◽  
The Impact

Recently, interest in the field of Vehicular Ad-hoc Networks (VANETs) has grown among research community to improve traffic safety and efficiency on the roads. Despite the many advantages, the transmission range in vehicular network remains one of the major challenges due to the unique characteristics of VANETs such as various communication environments, highly dynamic topology, high node mobility and traffic density. The network would suffer from a broadcast-storm in high vehicular density when a fixed transmission range in VANET is used, while in sparse vehicular density the network could be disconnected frequently. In this paper, we evaluated the impact of different transmission ranges and number of flows formed between vehicles in a highway scenario using AODV as routing protocol. In order to validate the simulation of VANET, traffic and network simulators (SUMO & NS-2) have been used. The performance was evaluated in terms of packet delivery ratio and end-to-end delay. The simulation results have shown that better performance was achieved in term of higher PDR and lower end-to-end delay for less than 500 meters transmission range. On the contrary, the PDR started to decrease and end-to-end delay increased when the transmission range exceeded 500 meters. The performance degraded as the number of flows increased.

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