58 research outputs found
Random Linear Network Coding for 5G Mobile Video Delivery
An exponential increase in mobile video delivery will continue with the
demand for higher resolution, multi-view and large-scale multicast video
services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a
number of new opportunities for optimizing video delivery across both 5G core
and radio access networks. One of the promising approaches for video quality
adaptation, throughput enhancement and erasure protection is the use of
packet-level random linear network coding (RLNC). In this review paper, we
discuss the integration of RLNC into the 5G NR standard, building upon the
ideas and opportunities identified in 4G LTE. We explicitly identify and
discuss in detail novel 5G NR features that provide support for RLNC-based
video delivery in 5G, thus pointing out to the promising avenues for future
research.Comment: Invited paper for Special Issue "Network and Rateless Coding for
Video Streaming" - MDPI Informatio
Random Linear Fountain Code with Improved Decoding Success Probability
In this paper we study the problem of increasing the decoding success
probability of random linear fountain code over GF(2) for small packet lengths
used in delay-intolerant applications such as multimedia streaming. Such code
over GF(2) are attractive as they have lower decoding complexity than codes
over larger field size, but suffer from high transmission redundancy. In our
proposed coding scheme we construct a codeword which is not a linear
combination of any codewords previously transmitted to mitigate such
transmission redundancy. We then note the observation that the probability of
receiving a linearly dependent codeword is highest when the receiver has
received k-1 linearly independent codewords. We propose using the BlockACK
frame so that the codeword received after k-1 linearly independent codeword is
always linearly independent, this reduces the expected redundancy by a factor
of three.Comment: This paper appears in: Communications (APCC), 2016 22nd Asia-Pacific
Conference o
Random Linear Network Coding for 5G Mobile Video Delivery
An exponential increase in mobile video delivery will continue with the demand for higher resolution, multi-view and large-scale multicast video services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a number of new opportunities for optimizing video delivery across both 5G core and radio access networks. One of the promising approaches for video quality adaptation, throughput enhancement and erasure protection is the use of packet-level random linear network coding (RLNC). In this review paper, we discuss the integration of RLNC into the 5G NR standard, building upon the ideas and opportunities identified in 4G LTE. We explicitly identify and discuss in detail novel 5G NR features that provide support for RLNC-based video delivery in 5G, thus pointing out to the promising avenues for future research
Datacenter Traffic Control: Understanding Techniques and Trade-offs
Datacenters provide cost-effective and flexible access to scalable compute
and storage resources necessary for today's cloud computing needs. A typical
datacenter is made up of thousands of servers connected with a large network
and usually managed by one operator. To provide quality access to the variety
of applications and services hosted on datacenters and maximize performance, it
deems necessary to use datacenter networks effectively and efficiently.
Datacenter traffic is often a mix of several classes with different priorities
and requirements. This includes user-generated interactive traffic, traffic
with deadlines, and long-running traffic. To this end, custom transport
protocols and traffic management techniques have been developed to improve
datacenter network performance.
In this tutorial paper, we review the general architecture of datacenter
networks, various topologies proposed for them, their traffic properties,
general traffic control challenges in datacenters and general traffic control
objectives. The purpose of this paper is to bring out the important
characteristics of traffic control in datacenters and not to survey all
existing solutions (as it is virtually impossible due to massive body of
existing research). We hope to provide readers with a wide range of options and
factors while considering a variety of traffic control mechanisms. We discuss
various characteristics of datacenter traffic control including management
schemes, transmission control, traffic shaping, prioritization, load balancing,
multipathing, and traffic scheduling. Next, we point to several open challenges
as well as new and interesting networking paradigms. At the end of this paper,
we briefly review inter-datacenter networks that connect geographically
dispersed datacenters which have been receiving increasing attention recently
and pose interesting and novel research problems.Comment: Accepted for Publication in IEEE Communications Surveys and Tutorial
Queue stability analysis in network coded wireless multicast.
In this dissertation queue stability in wireless multicast networks with packet erasure channels is studied. Our focus is on optimizing packet scheduling so as to maximize throughput. Specifically, new queuing strategies consisting of several sub-queues are introduced, where all newly arrived packets are first stored in the main sub-queue on a first-come-first-served basis. Using the receiver feedback, the transmitter combines packets from different sub-queues for transmission. Our objective is to maximize the input rate under the queue stability constraints. Two packet scheduling and encoding algorithms have been developed. First, the optimization problem is formulated as a linear programming (LP) problem, according to which a network coding based optimal packet scheduling scheme is obtained. Second, the Lyapunov optimization model is adopted and decision variables are defined to derive a network coding based packet scheduling algorithm, which has significantly less complexity and smaller queue backlog compared with the LP solution. Further, an extension of the proposed algorithm is derived to meet the requirements of time-critical data transmission, where each packet expires after a predefined deadline and then dropped from the system. To minimize the average transmission power, we further derive a scheduling policy that simultaneously minimizes both power and queue size, where the transmitter may choose to be idle to save energy consumption. Moreover, a redundancy in the schedules is inadvertently revealed by the algorithm. By detecting and removing the redundancy we further reduce the system complexity. Finally, the simulation results verify the effectiveness of our proposed algorithms over existing works
Ad-hoc Stream Adaptive Protocol
With the growing market of smart-phones, sophisticated applications that do extensive computation are common on mobile platform; and with consumers’ high expectation of technologies to stay connected on the go, academic researchers and industries have been making efforts to find ways to stream multimedia contents to mobile devices. However, the restricted wireless channel bandwidth, unstable nature of wireless channels, and unpredictable nature of mobility, has been the major road block for wireless streaming advance forward. In this paper, various recent studies on mobility and P2P system proposal are explained and analyzed, and propose a new design based on existing P2P systems, aimed to solve the wireless and mobility issues
Instantly Decodable Network Coding: From Point to Multi-Point to Device-to-Device Communications
The network coding paradigm enhances transmission efficiency by
combining information
flows and has drawn significant attention in information theory,
networking, communications
and data storage. Instantly decodable network coding (IDNC), a
subclass of network coding,
has demonstrated its ability to improve the quality of service of
time critical applications
thanks to its attractive properties, namely the throughput
enhancement, delay reduction,
simple XOR-based encoding and decoding, and small coefficient
overhead. Nonetheless, for
point to multi-point (PMP) networks, IDNC cannot guarantee the
decoding of a specific new
packet at individual devices in each transmission. Furthermore,
for device-to-device (D2D)
networks, the transmitting devices may possess only a subset of
packets, which can be used
to form coded packets. These challenges require the optimization
of IDNC algorithms to be
suitable for different application requirements and network
configurations.
In this thesis, we first study a scalable live video broadcast
over a wireless PMP network,
where the devices receive video packets from a base station. Such
layered live video has a
hard deadline and imposes a decoding order on the video layers.
We design two prioritized
IDNC algorithms that provide a high level of priority to the most
important video layer
before considering additional video layers in coding decisions.
These prioritized algorithms
are shown to increase the number of decoded video layers at the
devices compared to the
existing network coding schemes.
We then study video distribution over a partially connected D2D
network, where a group
of devices cooperate with each other to recover their missing
video content. We introduce
a cooperation aware IDNC graph that defines all feasible coding
and transmission conflictfree
decisions. Using this graph, we propose an IDNC solution that
avoids coding and
transmission conflicts, and meets the hard deadline for high
importance video packets. It is
demonstrated that the proposed solution delivers an improved
video quality to the devices
compared to the video and cooperation oblivious coding schemes.
We also consider a heterogeneous network wherein devices use two
wireless interfaces to
receive packets from the base station and another device
concurrently. For such network,
we are interested in applications with reliable in-order packet
delivery requirements. We
represent all feasible coding opportunities and conflict-free
transmissions using a dual interface
IDNC graph. We select a maximal independent set over the graph by
considering dual
interfaces of individual devices, in-order delivery requirements
of packets and lossy channel
conditions. This graph based solution is shown to reduce the
in-order delivery delay
compared to the existing network coding schemes.
Finally, we consider a D2D network with a group of devices
experiencing heterogeneous
channel capacities. For such cooperative scenarios, we address
the problem of minimizing
the completion time required for recovering all missing packets
at the devices using IDNC
and physical layer rate adaptation. Our proposed IDNC algorithm
balances between the
adopted transmission rate and the number of targeted devices that
can successfully receive
the transmitted packet. We show that the proposed rate aware IDNC
algorithm reduces the
completion time compared to the rate oblivious coding scheme
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