863 research outputs found
Instantly Decodable Network Coding: From Centralized to Device-to-Device Communications
From its introduction to its quindecennial, network coding has built a strong reputation for enhancing packet recovery and achieving maximum information flow in both wired and wireless networks. Traditional studies focused on optimizing the throughput of the system by proposing elaborate schemes able to reach the network capacity. With the shift toward distributed computing on mobile devices, performance and complexity become both critical factors that affect the efficiency of a coding strategy. Instantly decodable network coding presents itself as a new paradigm in network coding that trades off these two aspects. This paper review instantly decodable network coding schemes by identifying, categorizing, and evaluating various algorithms proposed in the literature. The first part of the manuscript investigates the conventional centralized systems, in which all decisions are carried out by a central unit, e.g., a base-station. In particular, two successful approaches known as the strict and generalized instantly decodable network are compared in terms of reliability, performance, complexity, and packet selection methodology. The second part considers the use of instantly decodable codes in a device-to-device communication network, in which devices speed up the recovery of the missing packets by exchanging network coded packets. Although the performance improvements are directly proportional to the computational complexity increases, numerous successful schemes from both the performance and complexity viewpoints are identified
CASPR: Judiciously Using the Cloud for Wide-Area Packet Recovery
We revisit a classic networking problem -- how to recover from lost packets
in the best-effort Internet. We propose CASPR, a system that judiciously
leverages the cloud to recover from lost or delayed packets. CASPR supplements
and protects best-effort connections by sending a small number of coded packets
along the highly reliable but expensive cloud paths. When receivers detect
packet loss, they recover packets with the help of the nearby data center, not
the sender, thus providing quick and reliable packet recovery for
latency-sensitive applications. Using a prototype implementation and its
deployment on the public cloud and the PlanetLab testbed, we quantify the
benefits of CASPR in providing fast, cost effective packet recovery. Using
controlled experiments, we also explore how these benefits translate into
improvements up and down the network stack
A Survey of multimedia streaming in wireless sensor networks: progress, issues and design challenges
Advancements in Complementary Metal Oxide Semiconductor (CMOS) technology
have enabled Wireless Sensor Networks (WSN) to gather, process and transport
multimedia (MM) data as well and not just limited to handling ordinary scalar
data anymore. This new generation of WSN type is called Wireless Multimedia
Sensor Networks (WMSNs). Better and yet relatively cheaper sensors that are
able to sense both scalar data and multimedia data with more advanced
functionalities such as being able to handle rather intense computations easily
have sprung up. In this paper, the applications, architectures, challenges and
issues faced in the design of WMSNs are explored. Security and privacy issues,
over all requirements, proposed and implemented solutions so far, some of the
successful achievements and other related works in the field are also
highlighted. Open research areas are pointed out and a few solution suggestions
to the still persistent problems are made, which, to the best of my knowledge,
so far have not been explored yet
- …