Ms. Lu Han Profile

Lu Han

at Tianjin Univ

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 2 October 2006 Paper

Implementation of an effective video transmission scheme over ad hoc networks

Lei Liu, Zhigang Jin, Yantai Shu, Linfang Dong, Lu Han

Proceedings Volume 6387, 63870H (2006) https://doi.org/10.1117/12.684376

KEYWORDS: Video, Image compression, Receivers, Image restoration, Image transmission, Cameras, Computer programming, Image segmentation, Video coding, Digital signal processing

Read Abstract +

Real-time video transmission over ad hoc networks faces many challenges including low bandwidth, long end-to-end delay, high packet loss rate, frequently changing topology and limited-powered mobile nodes. This paper presents an effective real-time video transmission scheme and improves implementation of DSR (Dynamic Source Routing) protocol. We set up a test-bed by using DSR routing in the IP layer, and an application transmitting video stream over UDP protocol. We get a continuous JPEG image stream from a ZC0301p web camera and split each image into small blocks according to the MCU (Minimum Coding Unit) borderline. The strong point of splitting JPEG image is that IP layer fragmentation can be avoided so we can determine which part of data in the frame gets lost to do loss recovery at the receiver. By using JPEG image stream, the video encoding complexity is reduced, which can save computing power of mobile nodes compared with MPEG and other Multiple Description Coding (MDC) methods. We also improve implementation of DSR to make it suitable to transfer real-time multimedia data. First different priorities are given to different traffic classes in DSR routing. Second the route maintenance scheme is modified to decrease overhead and link failure misjudgments. We carry out two experiments both indoors and outdoors using six mobile nodes. The first is to transmit continuous JPEG images using our former DSR implementation according to DSR draft. The second is that we split JPEG images into blocks and then transmit them using improved DSR implementation. Results show the latter gives better video stream fluency and higher image quality.

Proceedings Article | 2 October 2006 Paper

Decentralized session initiation protocol solution in ad hoc networks

Lu Han, Zhigang Jin, Yantai Shu, Linfang Dong

Proceedings Volume 6387, 63870D (2006) https://doi.org/10.1117/12.684253

KEYWORDS: Databases, Multimedia, Mobile devices, Network architectures, Control systems, Software development, Performance modeling, Receivers, Reliability, System integration

Read Abstract +

With the fast development of ad hoc networks, SIP has attracted more and more attention in multimedia service. This paper proposes a new architecture to provide SIP service for ad hoc users, although there is no centralized SIP server deployed. In this solution, we provide the SIP service by the introduction of two nodes: Designated SIP Server (DS) and its Backup Server (BDS). The nodes of ad hoc network designate DS and BDS when they join the session nodes set and when some pre-defined events occur. A new sip message type called REGISTRAR is presented so nodes can send others REGISTRAR message to declare they want to be DS. According to the IP information taken in the message, an algorithm works like the election of DR and BDR in OSPF protocol is used to vote DS and BDS SIP servers. Naturally, the DS will be replaced by BDS when the DS is down for predicable or unpredictable reasons. To facilitate this, the DS should register to the BDS and transfer a backup of the SIP users' database. Considering the possibility DS or BDS may abruptly go down, a special policy is given. When there is no DS and BDS, a new election procedure is triggered just like the startup phase. The paper also describes how SIP works normally in the decentralized model as well as the evaluation of its performance. All sessions based on SIP in ad hoc such as DS voting have been tested in the real experiments within a 500m*500m square area where about 30 random nodes are placed.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years