Giridhar D. Mandyam

ROUTE/DASH IP Streaming-Based System for Delivery of Broadcast, Broadband, and Hybrid Services

The delivery of digital television services over broadcast channels using the MPEG-2 transport stream (TS) is a well-established concept. Despite the success of this technology, the advances and success of Internet protocol (IP)-based delivery models with browser-centric media endpoints that combine broadband and broadcast technologies as well as new service requirements have resulted in alternatives to the MPEG-2 TS. These IP-based approaches are considered essential to maintaining the success of broadcast-centric television services. This paper discusses an IP centric approach which is respectful of clean layering and combines the over the top and the broadcast worlds. Central to this approach is a protocol named real-time object delivery over unidirectional transport (ROUTE), which is based IETF protocols such as layered coding transport over user datagram protocol. The dynamic adaptive streaming over HTTP format is used for both broadband and broadcast delivery. HTTP is used as the broadband delivery protocol, and ROUTE is used as the broadcast delivery protocol. It is demonstrated that the ROUTE-based approach is a lean and powerful media delivery method optimized for streaming media and non-real time media delivery with available application layer forward error correction. Thanks to its merits, this approach has been incorporated into the advanced television systems committee 3.0 design.

Improving battery life for wireless web services through the use of a mobile proxy

Cell phone battery life has been a fundamental design consideration ever since the first mobile devices were introduced in the 1970s. When mobile services were restricted to voice, the problem from a system design perspective often boiled down to finding best of breed components (e.g. amplifiers, signal processors, etc.) that optimized power while not sacrificing size. However, todays cell phones support a wide array of services beyond voice telephony, and battery life optimization is now being considered with respect to each of this multitude of services. Optimizing battery life for internet usage is a less constrained problem than optimization for voice telephony or audio and video playback. For starters, it is difficult to optimize the hardware in a mobile phone for a specific internet service given that there are many different types of services available over the internet (email, web, etc.). Nevertheless, almost all popular internet services that do not require a guaranteed level of quality-of-service (e.g. VoIP) can be delivered as web services wireless settings. As a result, power optimization in web transport mechanisms is an attractive area of focus for internet power optimization. In this work, the use of a mobile web proxy is considered as a means of increasing handset battery life for mobile web browsing. By leveraging observed user interaction with web content, the proxy can be designed to improve power consumption without sacrificing user experience.

Recommender systems for mobile content: Current challenges and ways forward

Cellular data services have benefited recently from enhancements in access speed, delay, and other parameters generally associated with quality-of-service (QoS). However, end users still often have trouble discovering appropriate content due to fractured and non-intuitive approaches to content discovery. One possible means of addressing this problem is the use of recommender systems to personalize content for cellular data users. Recommender systems have an established role in internet content discovery, but their applications in wireless are not straightforward. This paper discusses the critical challenges in implementing recommender systems for content in cellular systems, and also proposes methods for deployment of such systems so as to improve content discovery.

A Pilot-Aided Multicode CDMA Transmission Over Wireless Channels

To adapt to the time-varying multipath fading associated with the wireless link, we address the use of a pilot-aided fade-resistant transmission scheme based on the multicode code division multiple access (CDMA) technology. In this system, all the information symbols along with the pilot symbol of a user are transmitted simultaneously over the wireless channel. We apply matched filter receivers to estimate time-varying multipath channel coefficients and the contribution of the pilot signals is subtracted from the received signal prior to decoding the information symbols. We analyze the tradeoff between the number of diversity branches and the channel estimation error in the performance. Our study indicates that, depending on the transmitter power and the channel condition, the proposed system is capable of outperforming the conventional CDMA system with known channel state information at the receiver.

Traffic management for mobile broadband networks

Mobile terminals are becoming the primary Internet devices for most of the people in the world, and smartphone users are generating on average 10 times more traffic than other users. Current forecasts expect mobile data traffic to grow by 300?500 percent over the next 10 years, whereas the capacity of cellular infrastructure only doubles every two years. In order to cope with these challenges, it is critical that telecom operators and Internet service providers adopt smarter traffic management and pricing strategies. By 2020, more than half of the revenue in the global broadband industry is likely to be from two business models: ?wholesale? and ?two-sided? fees for improved access capacity and quality. These models require enforcement of stringent policy control mechanisms for bandwidth management, quality of service (QoS), and service level agreements.

Tiered attestation for Internet-of-Things (IoT) devices

Remote attestation is the procedure in which a relying party verifies the environment in which a device is carrying out cryptographic operations. Relying parties can leverage attestation data as part of their authentication and authorization procedures. However many Internet-of-Things (IoT) devices either do not have direct connectivity to relying parties, or may simply not be able to provide reliable attestation data. This paper introduces the concept of tiered attestation, where edge routing entities (i.e. gateways) can augment attestation data for relying parties while still accounting for limitations in the actual IoT devices.

Impact of HTML5 persistent connectivity to power consumption for the mobile web

With the advent of HTML5, the next generation of browser-based technologies for web developers, new connectivity paradigms have arisen that will allow web developers to move beyond HTTP-based stateless transactions. However, such new features do not transition seamlessly from the desktop to mobile browsers. Specifically, handheld devices with limited battery life can be impacted by persistent connectivity. In this work, two recent technologies (WebSockets and WebRTC) are examined with respect to power consumption. Based on this analysis, recommendations for improving battery life when using these technologies are provided.

Leveraging contextual data for multifactor authentication in the mobile web

Identify and authentication in the mobile web are important for many types of applications that benefit users, including payments. The mobile web today has several traditional approaches to authentication that allow for sensitive applications to take place. However, moving forward the use of contextual data can have a place in the area of authentication, Use of sensor information available on smartphones can provide information about user context that can serve either to augment existing authentication techniques or even provide additional authentication factors in their own right.

Power-efficient persistent web-based cellular connectivity

Web transactions are mostly stateless, and are driven by a request-response model originated by a web client (usually a browser). This works well for most types of web services. However, many types of web services require some form of two-way communications, such as browser-based instant messaging. This has lead to a proliferation of web services that employ polling techniques, which have several known drawbacks. Recently, WebSockets have been introduced as a browser-based solution that allows web applications to maintain a persistent TCP connection with a server. This enables web services to have true two-way messaging. Nevertheless, there are considerations web developers must take into account when leveraging WebSockets over cellular wireless access. This paper focuses on power consumption issues and proposes improvements to the WebSockets protocol.

Message from the steering committee co-chairs

It gives us a great pleasure to welcome the delegates to the Third International Conference on COMmunication Systems and NETworkS - COMSNETS 2011 held in Bangalore from 4 to 8 January 2011. The previous two editions of COMSNETS were a great success and we hope that the current edition of the conference will supersede the previous two in terms of quality and participation.