TAMA

Nowadays, static power consumption in chip multiprocessor (CMP) is the most crucial concern of chip designers. Power-gating is an effective approach to mitigate static power consumption particularly in low utilization. Network-on-Chip (NoC) as the backbone of multi- and many-core chips has no exception. Previous state-of-the-art techniques in power-gating desire to decrease static power consumption alongside the lack of diminution in performance of NoC. However, maintaining the performance and utilization of the power-gating approach has not yet been addressed very well. In this article, we propose TAMA (Turn-Aware Mapping & Architecture) as an effective method to boost the performance of the TooT method that was only powering on a router during turning pass or packet injection. In other words, in the TooT method, straight and eject packets pass the router via a bypass route without powering on the router. By employing meta-heuristic approaches (Genetic and Ant Colony algorithms), we develop a specific application mapping that attempts to decrease the number of turns through interconnection networks. Accordingly, the average latency of packet transmission decreases due to fewer turns. Also, by powering on turn routers in advance with lightweight hardware, the latency of sending packets diminishes. The experimental results demonstrate that our proposed approach, i.e., TAMA achieves more than 13% reduction in packet latency of NoC in comparison with TooT. Besides the packet latency, the power consumption of TAMA is reduced by about 87% compared to the traditional approach.

Practical cross-layer testing of HARQ-induced delay variation on IP/RTP QoS and VoLTE QoE

As the PHY/MAC-layer IR-HARQ and RLC-layer ARQ error recovery procedures, adopted in LTE, may impose additional delay when their code-block retransmissions occur, the arising question is whether these significantly contribute to IP and consequently RTP packet delays, and finally degrade the overall application-layer end-to-end QoE, especially when voice is transmitted over LTE? With this regard, we propose and demonstrate a VoLTE QoS and QoE test procedure based on PHY/MAC/RLC/IP/TCP-UDP/RTP cross-layer protocol analysis and perceptual speech quality QoE measurements. We identified monotonic relationship between the paired observations: QoE and HARQ RTT, i.e. between the PESQ voice quality rating and the IP/RTP packet latency, for given BLER of the received MAC/RLC code-blocks. Specifically, we found out that, for the HARQ RTT value of about 8 ms, only up to 2 HARQ retransmissions (and consequently no RLC-ARQ one) is appropriate during any voice packet, otherwise delay accumulation might not be accordingly “smoothed out” by jitter/playback buffers along the propagation path.

A Jamming-Resilient and Scalable Broadcasting Algorithm for Multiple Access Channel Networks

Multiple access channel (MAC) networks use a broadcasting algorithm called the Binary Exponential Backoff (BEB) to mediate access to the shared communication channel by competing nodes and resolve their collisions. While the BEB achieves fair throughput and average packet latency in jamming-free environments and relatively small networks, its performance noticeably degrades when the network is exposed to jamming or its size increases. This paper presents an alternative broadcasting algorithm called the K-tuple Full Withholding (KTFW), which significantly increases MAC networks’ resilience to jamming attacks and network growth. Through simulation, we compare the KTFW with both the BEB and the Queue Backoff (QB), an efficient and high-throughput broadcasting algorithm. We compare the three approaches against two different traffic injection models, each approximating a different environment type. Our results show that the KTFW achieves higher throughput and lower average packet latency against jamming attacks than both the BEB and the QB algorithms. The results also show that the KTFW outperforms the BEB for larger networks with or without jamming.

Trust-based energy-efficient routing protocol for Internet of things–based sensor networks

Internet of things grew swiftly and many services, software, sensors-embedded electronic devices and related protocols were developed and still in progress with full swing. Internet of things enabling physically existing things to see, hear, think and perform a notable task by allowing them to talk to each other and share useful information while making decision and caring-on/out their important tasks. Internet of things is greatly promoted by wireless sensor network as it becomes a perpetual layer for it. Wireless sensor network works as a base-stone for most of the Internet of things applications. There are severe general and specific threats and technical challenges to Internet of things–based sensor networks which must overcome to ensure adaptation and diffusion of it. Most of the limitations of wireless sensor networks are due to its resource constraint objects nature. The specified open research challenges in Internet of things–based sensor network are power consumption, network lifespan, network throughput, routing and network security. To overcome aforementioned problems, this work aimed to prolong network lifetime, improve throughput, decrease packet latency/packet loss and further improvise in encountering malicious nodes. To further tune the network lifetime in terms of energy, wireless harvesting energy is suggested in proposed three-layer cluster-based wireless sensor network routing protocol. The proposed mechanism is a three-tier clustering technique with implanted security mechanism to encounter malicious activities of sensor nodes and to slant them into blacklist. It is a centred-based clustering protocol, where selection of cluster head and grid head is carried out by sink node based on the value of its cost function. Moreover, hardware-based link quality estimators are used to check link effectiveness and to further improve routing efficiency. At the end, excessive experiments have been carried out to check efficacy of the proposed protocol. It outperforms most of its counterpart protocols such as fuzzy logic–based unequal clustering and ant colony optimization–based routing hybrid, Artificial Bee Colony-SD, enhanced three-layer hybrid clustering mechanism and energy aware multi-hop routing in terms of network lifetime, network throughput, average energy consumption and packet latency.

Quantizing Radio Link Data Rates to Create Ever-changing Network Conditions in Tactical Networks

Several sources of randomness can change the radio link data rate at the edge of tactical networks. Simulations and field experiments define these sources of randomness indirectly by choosing the mobility pattern, communication technology, number of nodes, terrain, obstacles and so on. Therefore, the distribution of change in the network conditions is unknown until the experiment is executed. We start with the hypothesis that a model can quantize the network conditions, using a set of states updated within a time window, to define and control the distribution of change in the link data rate before the experiment is executed. The goal is to quantify how much variation in the link data rate a tactical system can handle and how long it takes to resume IP data-flows after link disconnections. Our model includes functions to combine patterns of change together, transforming one pattern into another, jumping between patterns, and creating loops among different patterns of change. We use exemplary patterns to show how the change in the data rate impacts other link metrics, such as latency and jitter. Our hypothesis is verified with experiments using VHF radios over different patterns of change created by our model. We compute the inter-packet latency of three types of IP data-flows (broadcast, unicast and overlay) to highlight the time to resume data-flows after long link disconnections. The experimental results also support the discussion on the advantages and limitations of our model, which was designed to test tactical systems using military radios.

Quantizing Radio Link Data Rates to Create Ever-changing Network Conditions in Tactical Networks

Several sources of randomness can change the radio link data rate at the edge of tactical networks. Simulations and field experiments define these sources of randomness indirectly by choosing the mobility pattern, communication technology, number of nodes, terrain, obstacles and so on. Therefore, the distribution of change in the network conditions is unknown until the experiment is executed. We start with the hypothesis that a model can quantize the network conditions, using a set of states updated within a time window, to define and control the distribution of change in the link data rate before the experiment is executed. The goal is to quantify how much variation in the link data rate a tactical system can handle and how long it takes to resume IP data-flows after link disconnections. Our model includes functions to combine patterns of change together, transforming one pattern into another, jumping between patterns, and creating loops among different patterns of change. We use exemplary patterns to show how the change in the data rate impacts other link metrics, such as latency and jitter. Our hypothesis is verified with experiments using VHF radios over different patterns of change created by our model. We compute the inter-packet latency of three types of IP data-flows (broadcast, unicast and overlay) to highlight the time to resume data-flows after long link disconnections. The experimental results also support the discussion on the advantages and limitations of our model, which was designed to test tactical systems using military radios.

Validation of Hybrid Network-on-Chip Architecture for Optimized Performance using BookSim Simulator

Various complex integrated circuits suffer from the issues like poor connectivity, higher energy consumption and design productivity. One of the best solutions could be Network-on-Chip architecture which could solve the above issues. The Network-on-Chip architecture should be modelled and simulated well to evaluate the performance and analyse the cost. This paper presents a method to validate the proposed Network-on-Chip architecture with direct sequence spread spectrum using BookSim simulator. This simulation aims at validating the network parameters like packet latency and network latency. The detailed architectural parameters are compared and presented in this paper.

SSG - A Solution to Prevent Saturation Attack on the Data Plane and Control Plane in SDN/Openflow Network

The SDN/Openflow architecture opens new opportunities for effective solutions to address network security problems; however, it also brings new security challenges compared to the traditional network. One of those is the mechanism of reactive installation for new flow entries that can make the data plane and control plane easily become a target for resource saturation attacks with spoofing technique such as SYN flood. There are a number of solutions to this problem such as Connection Migration (CM) mechanism in Avant-Guard solution. However, most of them increase load to the commodity switches and/or split benign TCP connections, which can cause increase of packet latency and disable some features of the TCP protocol. This paper presents a solution called SDN-based SYN Flood Guard (SSG), which takes advantages of Openflow’s ability to match TCP Flags fields and the RST Cookie technique to authenticate three-way handshake processes of TCP connections in a separated device from SDN/Openflow switches. The experiment results reveal that SSG solves the aforementioned problems and improves the SYN Flood.