NDN Live Video Broadcasting over Wireless LAN
Menghan Li
∗
, Dan Pei
∗
, Xiaoping Zhang
∗
, Beichuan Zhang
†
,KeXu
∗
∗
Tsinghua National Laboratory for Information Science and Technology
Department of Computer Science and Technology, Tsinghua University
Email: limenghan12@mails.tsinghua.edu.cn, {peidan, zhxp, xuke}@tsinghua.edu.cn
†
Department of Computer Science, University of Arizona
Email: bzhang@cs.arizona.edu
Abstract—Named Data Networking (NDN) is a new Internet
architecture that replaces today’s focus on where – addresses
and hosts – with what – the content that users and applications
care about. One of NDN’s prominent advantages is scalable and
efficient content distribution due to its native support of caching
and multicast in the network. However, at the last hop to wireless
users, often the WiFi link, current NDN implementation still
treats the communication as multiple unicast sessions, which will
cause duplicate packets and waste of bandwidth when multiple
users request for the same popular content. WiFi’s built-in
broadcast mechanism can alleviate this problem, but it suffers
from packet loss since there is no MAC-layer acknowledgement
as in unicast. In this paper, we develop a new NDN-based
cross-layer approach called NLB for efficient and scalable live
video streaming over wireless LAN. The idea is to use WiFi’s
broadcast channel to deliver content from the access point
to the users, a leader-based mechanism to suppress duplicate
requests from users, and receiver-driven rate control and loss
recovery. The design is implemented and evaluated in a physical
testbed comprised of a commodity residential access point and 20
WiFi clients. While NDN with multiple unicast sessions or plain
broadcast can support no more than 7 concurrent viewers of a
1Mbps streaming video, NDN plus NLB supports all 20 viewers,
and can likely support many more when present.
I. INTRODUCTION
A major trend of Internet traffic in the last few years
is the fast increase of video content. For example, in North
America, Netflix as a video streaming company has become
the largest source of Internet traffic, consuming 29.7% of peak
downstream traffic [1]. Another major trend is the proliferation
of mobile devices, such as smartphones, tablets and laptops.
Subsequently, more and more contents, especially video con-
tents, are consumed on wireless mobile devices, and because of
the cost advantage of WiFi over cellular, most video contents
are consumed over WiFi links as the last hop to the users.
According to a recent forecast by Cisco [2], 61% Internet
access will be over WiFi and mobile devices by 2018.
The need for efficient and scalable video distribution has
not only driven the upgrade and expansion of operational
networks, but also the development of new network designs
and architectures. Named Data Networking (NDN) [3] is a new
Internet architecture that emphasizes the content itself rather
than its container (e.g., host) or channel (e.g., connection).
By including the content name in each packet, NDN enables
native multicast and caching support in the network, which
will greatly improve large-scale content distribution, including
video distribution.
∗
Xiaoping Zhang is the corresponding author.
While video streaming has already received considerable
attention in the NDN research community in [4]–[11], little
research work has been done on scalable and efficient video
streaming over WLAN. In broadcast media such as WLAN,
content delivery will benefit significantly if content is broad-
casted to multiple clients when they are requesting for the same
popular content. However, in IP networks, multiple clients in
the same WLAN are served via multiple unicast sessions,
resulting in duplicate data packets and waste of bandwidth.
The current NDN implementation, running as overlay on top
of IP, suffers from the same problem of not being able to take
advantage of the broadcast nature of underlying media. This
inefficiency at the last hop may negate all NDN’s benefits in
wired networks for content distribution.
In this paper, we develop an efficient and scalable solution
for NDN live video streaming over WLAN. Live video stream-
ing has more stringent performance requirements than Video-
on-Demand (VoD), because it cannot prefetch the content from
servers to caches which are much closer to the clients as in
VoD. The time interval for buffering live stream cannot be too
large and the transmission rate must satisfy the stream bit rate.
In fact, live video streaming has to deal with a specific class
of problems to ensure timely delivery of an ordered stream of
video chunks.
Furthermore, live video streaming over WiFi has important
use scenarios. For example, campus-wide live speech with
thousands to tens of thousands of viewers in a company or a
university [12], country-wide live events such as SuperBowl,
NBA finals, World Cup games, Olympic Opening ceremonies,
president’s speech etc. As the popularity of mobile devices
keeps increasing, people will more and more to use mobile
devices to watch these live events online over WiFi.
For the above reasons, we believe that supporting live video
broadcasting over WiFi has important real-world impacts, and
that leveraging and extending NDN protocols is one promising
direction to approach this problem.
Our basic idea is to use WLAN’s built-in broadcast to
deliver the same piece of Data once to multiple clients at the
same time, and make it efficient and robust. The proposed
approach, called NDN Live video Broadcasting (NLB), is
a combination of NDN layer and application layer mecha-
nisms (both above the MAC layer) and does not require any
modification to the 802.11 MAC layer. Therefore, NLB is
different from and complement previous work that provides
802.11 broadcasting/multicasting mechanism via packet re-
transmission, ordering, network coding, or PHY rate adapting,
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