Efficient communication over cellular networks with network coding in emergency scenarios

Network coding (NC) and erasure coding (EC) share a common principle of encoding incoming data packets at network intermediate nodes so that destination nodes can reconstruct the original data packets using a sufficient number of encoded data packets collected at the destinations. While NC in general reduces the number of packets sent through the network, EC introduces redundancy into the packet streams to recover from lost packets. Many research papers in NC assume loss-free packet transmission, and to address this issue, end-to-end packet loss recovery through EC has been proposed. In this paper, we investigate hop-by-hop packet loss recovery through EC so as to avoid the accumulation of lost packets throughout the network using flow oriented EC. Specifically, we explore combined NC and EC at intermediate nodes in the networks to allow for improved packet loss recovery compared to end-to-end EC. Different implementations trading the packet processing complexity at the intermediate and destination nodes are considered. This paper first examines the effects of data loss in NC and then the improvements achievable with the proposed method are presented.

Emergency response services are often delayed due to the destruction or non-availability of the communication network. This research work proposes Mobile Adhoc NETwork (MANET) architecture integrated with mobile sensing concepts, for reviving the communication network in disaster hit areas. Mobile sensing in emergency scenarios can very well address issues like victim localization etc. and offer help in providing specific information about the affected area to the responders and control stations. This paper proposes a design that utilizes the existing the mobile devices such as smartphones, laptops, etc. in the field to provide the required communication facility. A new buffer system powered flooding methodology is also proposed to cater to the challenging environment. The mobile adhoc network architecture proposed is implemented and tested using several android based mobile phones. An android application named Android app for Emergency Communication (AEC) was developed and it enabled users to send messages to emergency services as well as their dear ones even when they are in regions with no cellular coverage.

In this paper we are interested in improving the performance of constructive network coding schemes for video transmission over packet lossy networks. A novel unequal packet loss protection scheme R2NC based on low-triangular global coding matrix with ladder-shaped partition will be presented, which combines redundant and random network coding for robust H.264/SVC video transmission. Firstly, the error-correcting capabilities of redundant network coding make our scheme resilient to loss. Secondly, the implementation of random network coding at the intermediate nodes with multiple input links can reduce the cost of network bandwidth, thus reducing the end to end delay for video transmission. Thirdly, the low-triangular global coding matrix with ladder-shaped partition is maintained throughout R2NC process to provide unequal erasure protection for H.264/SVC priority layers. The redundant network coding avoids the retransmission of lost packets and improves error correcting capabilities of lost packets. Based only on the knowledge of the loss rates on the output links, the source node and intermediate nodes can make decisions for redundant network coding and random network coding (i.e., how much redundancy to add at this node). However, the redundancy caused by redundant network coding makes the network load increases, in order to improve network throughput, we perform random network coding at the intermediate nodes. Our approach is grounded on the overall distortion of reconstructed video minimization by optimizing the amount of redundancy assigned to each layer. Experimental results are shown to demonstrate the significant improvement of H.264/SVC video reconstruction quality with R2NC over packet lossy networks.

Connectivity, losses, and buffering are factors that directly affect the performance of network coding. These factors affect the ability of intermediate nodes to generate useful encodings; these are encodings that contribute in propagating and recovering data at receiver node(s). It has been shown that in particular scenarios network coding performance can be improved by simply increasing the generation size (k); however, this leads to increasing transmission overhead, encoding complexity and (more importantly) buffer sizes at intermediate nodes. In this paper, we propose a new network coding approach where we employ Multi-Generation Mixing (MGM). MGM eliminates the need to increasing buffer sizes while improving the performance of network coding. Under MGM, we define a mixing set of size m generations that can be network coded (mixed) together. Within each MGM mixing set, a new set of generation packets are mixed with previously transmitted (network coded) generations. This generalized approach provides a great deal of resilience against losses when compared with traditional generation-based network coding. Our analysis of the performance of MGM-based network coding demonstrates significant reduction in required overhead for a given recovery performance at the receivers. We also illustrate the performance of MGM using extensive simulations that provide a useful insight into the viability of MGM-based network coding.

In a classical network, data streams originating from a source and intended to a desired destination are routed through intermediate nodes before reaching their final destination. By contrast, Network Coding (NC) manipulates at an intermediate node those data streams by combining the data from the streams before forwarding it to the destination. This paper describes the advances of NC in wireless communication for IMT-Advanced and beyond. A short overview of NC in wireless communications is given first. Afterward, the application of NC to broadcasting is described. Thereafter, NC methods in uplink wireless communications, such as User Grouping (UG) and Relay Selection (RS) are described. Further, the advantage of non-binary over binary network NC is shown in a multi-user multi-relay scenario. Finally the performance of NC is analyzed. In particular, in the uplink Multiple Access Relay Channel (MARC) scenario, the joint UG and RS methods lift the system capacity by 70%. The non-binary NC improves the SNR up to 4 dB. Finally the efficient broadcast method yields up to 22% overhead reduction compared to ARQ.

Chapter 1 - An Introduction to Network Coding

Network coding is a promising technology to improve throughput and reliability. However, the benefit of network coding is restricted and affected by network topology, especially in peer-to-peer system. Precise topology awareness can be helpful to improve system performance of network coding in terms of throughput and reliability. In this paper, we propose an innovative scheme TANCF (Topology Awareness based on Network Coding with Feedback), to detect the path in hierarchical P2P network based on the feedback from the intermediate nodes and the receiver nodes of network coding system. It is a first attempt to use network coding with feedback to reveal the network connectivity and to construct the network topology. In the TANCF scheme, the path matrix of network can be obtained by the feedback from intermediate nodes and receiver nodes, which has a close relationship with the adjacency matrix of topology, so that it can be used to construct the network topology that lead to optimize the parameters of network coding. Through the matrix analysis and simulation experiment, it can be proved that TANCF scheme can obtain the path matrix correctly with a high probability.

We consider Delay Tolerant Mobile Social Networks (DTMSNs), made of wireless nodes with intermittent connections and clustered into social communities. The lack of infrastructure and its reliance on nodes' mobility make routing a challenge. Network Coding (NC) is a generalization of routing and has been shown to bring a number of advantages over routing. We consider the problem of pollution attacks in these networks, that are a very important issue both for NC and for DTMSNs. Our first contribution is to propose a protocol which allows controlling adversary's capacity by combining cryptographic hash dissemination and error-correction to ensure message recovery at the receiver. Our second contribution is the modeling of the performance of such a protection scheme. To do so, we adapt an inter-session NC model based on a fluid approximation of the dissemination process. We provide a numerical validation of the model. We are eventually able to provide a workflow to set the correct parameters and counteract the attacks. We conclude by highlighting how these contributions can help secure a real-world DTMSN application (e.g., a smart-phone app.).

With more and more multimedia applications on the Internet, such as IPTV, bandwidth becomes a vital bottleneck for the booming of large scale Internet based multimedia applications. Network coding is recently proposed to take advantage to use network bandwidth efficiently. In this paper, we focus on massive multimedia data, e.g. IPTV programs, transportation in peer-to-peer networks with network coding. By through study of networking coding, we pointed out that the prerequisites of bandwidth saving of network coding are: I) one information source with a number of concurrent receivers, or 2) information pieces cached at intermediate nodes. We further proof that network coding can not gain bandwidth saving at immediate connections to a receiver end; As a result, we propose a novel model for IPTV data transportation in unstructured peer-to-peer networks with network coding. Our preliminary simulations show that the proposed architecture works very well.

It has been shown in the literature that Network Coding (NC) can boost the performance of wireless networks. However, to really obtain the potential gain of NC, efficient Medium Access Control (MAC) protocols that operate with awareness of the NC functions are necessary. In this paper, we propose a novel NC-aware MAC protocol for IEEE 802.11 wireless networks that combines k-batch transmissions and multiple receiver-initiated reverse direction exchanges involving NC data to boost the overall network performance. The proposed protocol allows any node to transmit a burst of data packets in a single channel access invocation. Then, an intermediate node can transmit an NC data packet when receiving a valid data packet from a source node, without contending for channel access. Both analytical and simulation results presented in this paper show the high throughput and energy efficiency of the proposed protocol with gains ranging from 33% to 298% when compared to existing mechanisms based on the IEEE 802.11 Standard.∗

Nowadays, video streaming has became one of the most popular multimedia applications and will be the dominant data traffic in cellular networks. This is a real challenge for mobile network operators because the cellular base stations will be overloaded. One promising solution to offload mobile traffic from the base stations is the use of Device-to-Device (D2D) communications. Each mobile phone can use both cellular and Wi-Fi network interfaces to download video segments either from the Internet or from a neighboring device. However, it is crucial to improve the reliability of D2D communications to maximize the offloading benefits. In this paper, we use network coding to address the reliability in cooperative D2D-based transmission of video streaming. We have implemented Random Linear Network Coding (RLNC) on the CoopStreaming system and evaluate the offloading gain. The experimental results show that the use of network coding has significantly improved the reliability of D2D communications among neighboring devices and therefore increased the cellular offloading gain.

Network coding, a networking paradigm in which different pieces of data are coded together at various points along a transmission, has been proposed for providing a number of benefits to networks including increased throughput, robustness, and security. For optical networks, the potential for using network coding to provide survivability is especially noteworthy as it may be possible to allow for the ultra-fast recovery time of dedicated protection schemes with the bandwidth efficiency of shared protection schemes. However, the need to perform computations at intermediate nodes along the optical route leads to the undesirable necessity of either electronically buffering and processing the data at intermediate nodes or outfitting the network with complex photonic circuits capable of performing the computations entirely within the optical domain. In this paper, we take the latter approach but attempt to mitigate the impact of the device complexity by proposing a low-complexity, all-optical network coder architecture. Our design provides easily scalable, powerful digital network coding capabilities at the optical layer, and we show that existing network coding algorithms can be adjusted to accommodate it.

Network coding is a proposed technique for improving network capacity. This novel concept has been mainly oriented to increase throughput and reliability of communication networks. Network coding is implemented in the intermediate nodes before forwarding the encoded packets to the end nodes. The received packets are decoded in the end nodes in order to recovery the original transmitted data (video data in our case). In this work, we investigate the performance of network coding in collaborative multi-source scenarios with heterogeneous resources (video, image, audio, pdf files). Collaborative multi-source schemes are very important for critical multimedia services because multimedia content consumes an important amount of resources in the communication networks. A multi-source scheme is a useful solution when different parts of a multimedia content is generated or stored in two or more sites. Our evaluation compares the performance of a P2P networking with network coding against a client-server communications. Results show great benefits on using network coding scheme in collaborative multi-source scheme.

We propose a network information flow strategy of optimal multicast with erasure correction coding (OMEC), in which erasure correction is a means of utilizing diversities rather than combating packet losses. An information source is first encoded by an erasure correction code and then optimally multicast by a server to sinks. The OMEC scheme has the following characteristics: (1) It is at least as good as optimal routing and, for some cases, can realize a network throughput arbitrarily larger than that achievable by pure routing. (2) For most scenarios, the approach yields a throughput comparable with the optimal throughput achievable with network coding. In fact, for most examples in the literature for which network coding makes high throughput gains compared to pure routing, OMEC performs close to the optimal. (3) Unlike general network coding, intermediate nodes are only required to route information. This makes OMEC compatible with currently deployed network structures. (4) Surprisingly, unlike pure optimal routing, OMEC can be efficiently computed in polynomial time. While OMEC is, in general, suboptimal compared to full fledged network coding, it enjoys most of the computational and throughput benefits associated with network coding over pure routing, without requiring any changes to existing hardware infrastructures or protocol stacks

Network coding (NC) is a promising technique recently proposed to improve network performance in terms of maximum throughput, minimum delivery delay, and energy consumption. The original proposal highlighted the advantages of NC for multicast communications in wire-line networks. Recently, network coding has been considered as an efficient approach to improve performance in wireless networks, mainly in terms of data reliability and lower energy consumption, especially for broadcast communications. The basic idea of NC is to remove the typical requirement that different information flows have to be processed and transmitted independently through the network. When NC is applied, intermediate nodes in the network do not simply relay the received packets, but they combine several received packets before transmission. As a consequence, the output flow at a given node is obtained as a linear combination of its input flows. This chapter deals with the application of network coding principle at different communications layers of the protocol stack, specifically, the Medium Access Control (MAC) and physical (PHY) Layers for wireless communication networks.