Transcript Design of a Mobile TV Testbed - network systems lab @ sfu

Designing an Efficient and Extensible
Mobile TV Testbed
Cheng-Hsin Hsu
Simon Fraser University, Canada
joint work with Mohamed Hefeeda,
Yi Liu, and Cong Ly
Mobile TV Service



Broadcast mass-market programs to subscribers
Mobile devices have stringent energy budgets
Devices receive a data burst and turn off receiving
circuits until the next burst  called time slicing
2
Mobile TV Networks
Content
Providers
Streaming
Server
Network Operators
Base Station
Multiplexer
Modulator/
Amplifier
(IP Encapsulator)
Camera
IP Networks



ASI Networks
Program feeds are IP streams from streaming
servers or cameras
Multiple TV programs are multiplexed AND time
sliced by a multiplexer into a MPEG-2 TS stream
The MPEG-2 TS stream is modulated, amplified,
and broadcast to mobile devices
3
Problem Statement

Design a mobile TV base station for academic
prototyping and cost-efficient small- to mediumsize deployments
 platform to analyze: energy consumption,
channel switching delay, no. broadcast
programs, and perceived streaming quality
 10-20 TV channels with a commodity PC or
low-end server
4
Current Solutions (1/2)

Commercial Base Stations
 expensive, e.g., a single EXPWAY FastESG
server costs 75k USD [Sarri09]
 a complete base station costs even more
Need a more cost-efficient
base station!
5
Current Solutions (2/2)
Python
Sources
For PSISI
VLC
Server
MPEG

TS Packets
Python
Compiler
Data
Aggregator
x20?
Time
Slicer
Pcap
Null Packet
Replacer
TS
Tdt
Updater
w/PSISI
Dtplay
Correct PSISI
Open-Source Base Station [FATCAPS]
 too many disk I/O’s
 does not scale well
 too many utilities with no admin interface
Need a better design!
6
Design Goals




[G1] Higher efficiency and scalability
 avoid disk I/O’s and memcpys
[G2] Utilization of multi-core processors
 pipelined structure to allow parallelism
[G3] Integrated software solution
 centralized admin interface
[G4] Better extensibility
 future supports for other networks such as
MediaFLO, WiMAX, and MBMS
7
Design Decisions (1/3)

[D1] Use Burst as the unit of time slicing,
encapsulation, and transmission.

Burst is self-contained with IP payloads and
headers/trailers of all protocols

No disk I/O’s for intermediate data

No memcpys for IP payloads
8
Design Decisions (2/3)

[D2] Divide the base station into three indep.
Phases, which are connected by two priority queue
 pipelined and parallelism
Request
Queue
Empty
Burst
Time
Slicing
Thread
With IP
Payload
Encap.
Thread
With All
Headers
/Trailers
Ready
Queue
Trans.
Thread
Encap.
Thread
Encap.
Thread
9
Design Decisions (3/3)

[D3] Implement a centralized Configuration
Manager to allow save/restore settings
 interface with Web GUI for management

[D4] Modularized design for future extensions
 For example, MPE-FEC Burst is a subclass of
MPE Burst
10
Software Architecture
11
High-Level Design
12
Design of Burst Schedulers
13
Design of Burst Readers
14
Design of Bursts
15
Design of Encapsulators
16
Design of Transmitter
17
Design of PSI/SI Tables






PAT: program association
PMT: program map
NIT: network information
INT: IP/MAC notification
SDT: service description
TDT: time and date
18
Design of Configuration Manager
19
Testbed Setup
20
Future Work






Web GUI for configuration management [Cong]
MPE-FEC support [Hamed]
PSI/SI table implementation [Farid]
StreamReader classes [Som]
Flute server integration
ESG files implementation
21
Conclusions

Presented layout of general broadcast network

Outlined design goals of a broadcast base station

Described our design decisions and system
architecture

Presented the high-level system design and detailed
design for each component

Highlighted future work
22
Thank You, and Questions?
More details can be found online at http://nsl.cs.sfu.ca
23