Dynamic Composable Computing Roy Want, Trevor Pering, Shivani Sud and Barbara Rosario Intel Research 2200 Mission College Blvd Santa Clara, CA 95024 Email: {roy.want, trevor.pering, shivani.a.sud, barbara.rosario}@intel.com 1. Introduction In the last 10 years, personal computing has evolved from being primarily a desktop activity to a highly mobile one: the laptop computer, despite its large size and significant weight, has been the most popular mobile platform to date. While smart phones and MIDs (Mobile Internet Devices) have made in-roads into general computing applications, their use is limited to a few key tasks (e.g., calendar, rolodex, mp3 player) that are suited to the small size of their keypad and screen. However, given ever increasing processing and storage capabilities, the potential of these devices far exceeds the computational needs of these applications, and a significant problem facing the mobile industry is how to give users access to a full personal computing experience [9] with the mobility afforded by a smart phone or MID. This paper proposes a solution to this problem called Dynamic Composable Computing (DCC), which enables the impromptu assembly of a logical computer from the best set of wireless component parts available nearby. Consider the following example which illustrates the goals and flexibility we are trying to achieve with DCC: Fred and Sally are visiting their friend Joe’s house when the topic of Sally’s recent vacation comes up. Instead of just showing them pictures on her mobile device, Sally displays a collection of her favorite pictures on Joe’s wall-mounded flat- screen TV, using her mobile device to advance slides. Meanwhile, Fred takes a moment to browse through Joe’s music collection on his mobile device until he finds an appropriate album, which he then triggers to play on Joe’s stereo system. Our contributions in this paper include: 1) identifying the issues that make dynamic compositions unique, 2) presenting an overview of technology trends that make composition practical today and 3) reporting on the design and experiences of an initial prototype system. In practice, a mobile device will always be designed based on a compromise that trades-off size, weight, processing power, storage, communication bandwidth, and battery lifetime. DCC aims to overcome these basic design limitations by enabling a platform that is more than the sum of its components: allowing users to easily and seamlessly extend the capabilities of their mobile device with the nearby resources in their environment, and further allow its resources to augment other devices in the locality. 2. Technology Enablers for DCC There are three emerging technology pillars that support Dynamic Composable Computing: wireless communication, effective processing, and platform sensing. First, wireless standards provide the ease of creating dynamic connections without requiring a user to physically plug mobile and infrastructural components together. Towards this end, two wireless standards, Ultra-Wideband (UWB)[2] and WiFi-n[14] are now commercially available and enable data transfers up to 480Mbps and 540Mbps, respectively. This improves the throughput of the wireless peripherals making them available at speeds comparable to a wired computer-bus: For the first time we can consider connecting the major system components of a computer architecture using wireless links. Of these two radio options, UWB is likely to be better suited to support composability because the ECMA WiMedia protocol design (Phy & Link Layer) [2] is more power efficient using a timeslot reservation scheme, in combination with a sleep mechanism for unused slots. This is in contrast to WiFi solutions that are based on contention networks, and therefore each node must always be awake and listening to ensure reception of packets. Second, continuing trends in processor technology are enabling new levels of interoperability between mobile devices and desktop processing ecosystems. Existing low-power processors are improving and even now are powerful enough to effectively run an embedded Linux operating system in a handset; however, they fall short when tasked to run a full desktop suite of applications, including animations, memory- intensive applications, security protection. Furthermore, the general operating environment for mobile devices is different and impoverished when compared with a desktop system, preventing many internet features and plug-ins from operating correctly in a small environment. Solving this problem, a new breed of low-power desktop-compatible processors are entering the market, targeted at MIDs, and expected to bridge the