Cache-Version Selection and Content Placement for Multi-Resolution Video Streaming in Information-Centric Networks

Information Centric Networks (ICN) is an infrastructure that focuses on information retrieval rather than end to end connections. ICN uses 2 features - name based routing and in-network caching in order to attain better performance. Named Data Networks (NDN) is an architecture for Information Centric Networks (ICN). In this thesis, we implement a version selection cum content placement policy (CaVe-CoP) that takes advantage of both features. We focus on multi-resolution video streaming and implement a scheme where only an optimal set of resolutions of videos need to be cached in order to obtain higher network utility. This distinction between multiple resolutions of the same video is possible today because of the varied devices available for video streaming that have different resolution constraints. We first formulate and solve an optimization problem for version selection and content placement in a generic network that supports multi-resolution video streaming and has in-network caches. Next, we implement the solution in an NDN-compliant framework (ndnSIM) as a distributed algorithm. We compare our policy against 2 other policies - 1) where all resolutions of a content are cached, and 2) where the user opts for a greedy version selection. Our simulations on general network topologies show a fast convergence rate, higher utility and a lower stall time in comparison to both these policies

Fronthaul-Constrained Cloud Radio Access Networks: Insights and Challenges

As a promising paradigm for fifth generation (5G) wireless communication systems, cloud radio access networks (C-RANs) have been shown to reduce both capital and operating expenditures, as well as to provide high spectral efficiency (SE) and energy efficiency (EE). The fronthaul in such networks, defined as the transmission link between a baseband unit (BBU) and a remote radio head (RRH), requires high capacity, but is often constrained. This article comprehensively surveys recent advances in fronthaul-constrained C-RANs, including system architectures and key techniques. In particular, key techniques for alleviating the impact of constrained fronthaul on SE/EE and quality of service for users, including compression and quantization, large-scale coordinated processing and clustering, and resource allocation optimization, are discussed. Open issues in terms of software-defined networking, network function virtualization, and partial centralization are also identified.Comment: 5 Figures, accepted by IEEE Wireless Communications. arXiv admin note: text overlap with arXiv:1407.3855 by other author

Relaying in the Internet of Things (IoT): A Survey

The deployment of relays between Internet of Things (IoT) end devices and gateways can improve link quality. In cellular-based IoT, relays have the potential to reduce base station overload. The energy expended in single-hop long-range communication can be reduced if relays listen to transmissions of end devices and forward these observations to gateways. However, incorporating relays into IoT networks faces some challenges. IoT end devices are designed primarily for uplink communication of small-sized observations toward the network; hence, opportunistically using end devices as relays needs a redesign of both the medium access control (MAC) layer protocol of such end devices and possible addition of new communication interfaces. Additionally, the wake-up time of IoT end devices needs to be synchronized with that of the relays. For cellular-based IoT, the possibility of using infrastructure relays exists, and noncellular IoT networks can leverage the presence of mobile devices for relaying, for example, in remote healthcare. However, the latter presents problems of incentivizing relay participation and managing the mobility of relays. Furthermore, although relays can increase the lifetime of IoT networks, deploying relays implies the need for additional batteries to power them. This can erode the energy efficiency gain that relays offer. Therefore, designing relay-assisted IoT networks that provide acceptable trade-offs is key, and this goes beyond adding an extra transmit RF chain to a relay-enabled IoT end device. There has been increasing research interest in IoT relaying, as demonstrated in the available literature. Works that consider these issues are surveyed in this paper to provide insight into the state of the art, provide design insights for network designers and motivate future research directions