21264133
Wave-pipelined multiplexed (WPM) routing for gigascale integration (GSI)
In modern-day VLSI systems, performance and manufacturing costs are being driven by the on-chip wiring needs due to the continuous increase in the number of transistors. This paper proposes a low overhead wave-pipelined multiplexed (WPM) routing technique that harnesses the inherent intraclock period interconnect idleness to implement wire sharing throughout the various hierarchical levels of design. It is illustrated in this paper that the WPM network can be readily incorporated into future gigascale integration (GSI) systems to reduce the number of interconnect routing channels in an attempt to contain escalating manufacturing costs. Both, a system level analysis and circuit level verification of this WPM routing are presented in this paper. A multilevel interconnect network design simulator (MINDS) that uses system level interconnect prediction (SLIP) techniques and HSPICE circuit simulations for optimizing the interconnect dimensions has been used to assess the opportunities for application of WPM wire circuits in high performance digital designs. A custom routing example highlights the ease with which the WPM routing technique can be easily incorporated into the existing VLSI systems. In addition, for a 40 million transistor system case study, this system level analysis reveals that the use of a WPM network could result in an almost 20% decrease in the number of metal layers for less than 4% increase in dynamic power with no loss of communication throughput performance. The key virtues of WPM routing are its flexibility, robustness, implementation simplicity and its low overhead requirements.
6625273
Wave-pipelined 2-slot time division multiplexed (WP/2-TDM) routing
The ever-increasing number of transistors on a chip has resulted in very large scale integration (VLSI) systems whose performance and manufacturing costs are driven by on-chip wiring needs. This paper proposes a low overhead wave-pipelined two-slot time division multiplexed (WP/2-TDM) routing technique that harnesses the inherent intra-clock period wire idleness to implement wire sharing in combination with wave-pipelined circuit techniques. It is illustrated in this paper that WP/2-TDM routing can be readily incorporated into future gigascale integration (GSI) systems to reduce the number of interconnect routing channels in an attempt to contain escalating manufacturing costs. Two case studies, one at the circuit level and one at the system level, are presented to illustrate the advantages of WP/2-TDM routing. The circuit level implementation exhibits more than 40% reduction in wire area, a 30% reduction in silicon area with no increase in dynamic power and no loss of throughput performance.
1644414
A 2-slot time-division multiplexing (TDM) interconnect network for gigascale integration (GSI)
In many wire-limited VLSI digital systems the time delay of the longest global interconnect can be a significant percentage of the clock period. However, because semi-global and global wires with shorter wire lengths can have a much smaller time delay, they can remain idle (i.e. not switching) for a significant portion of the clock period even after their data has been transmitted. To capitalize on this phenomenon, this paper proposes that a low-overhead 2-slot Time Division Multiplexing (TDM) network should be incorporated into the multilevel interconnect architectures of future GSI systems to help reduce the escalating manufacturing costs that are primarily due to the projected increase in the number of metal layers. Using system-level interconnect prediction (SLIP) techniques, it is shown that a 20% reduction in the number of metal levels could be achieved for a 100M transistor VLSI system with only a 5-10% increase in power dissipation.
498300
Low power multilevel interconnect networks using wave-pipelined multiplexed (WPM) routing
A low power multilevel interconnect architecture that uses wave-pipelined multiplexed (WPM) interconnect routing is proposed in this paper. WPM takes advantage of existing interconnect idleness and implements low-overhead wire sharing to reduce the number of routing tracks required for intra-macrocell communication. It is shown that the extra available routing area could then be used to redesign the interconnect network to substantially reduce coupling capacitance and driver sizes. System-level simulation reveals that the systematic application of WPM reduces total power of a 40M transistor macrocell by almost 28% without any loss in performance.
43473572
Integrating service discovery with routing and session management for ad-hoc networks
In this paper, we propose GSR: a new routing and session management protocol for ad-hoc networks as an integral part of a service discovery infrastructure. Traditional approaches place routing at a layer below service discovery. While this distinction is appropriate for wired networked services, we argue that in ad-hoc networks this layering is not as meaningful and show that integrating routing with discovery infrastructure increases system efficiency. Central to our protocol is the idea of reusing the path created by the combination of a service discovery request and a service advertisement for data transmission. This precludes the need to use separate routing and discovery protocols. GSR also combines transport layer features and provides end-to-end session management that detects disconnections, link and node failures and enables service-centric session redirection to handle failures. This enables GSR to accommodate service-centric routing apart from the traditional node-centric routing. We compare GSR with AODV in terms of packet delivery ratio, response time and average number of hops traveled by service requests as well as data. GSR achieves better packet delivery ratio with a minor increase of the average packet delivery delay.
5158303
An active transcoding proxy to support mobile web access
In this paper, we present a proxy based system (MOWSER) to support web browsing from mobile clients over wireless networks. Mowser is a proxy agent between the mobile host and the web server, which performs active transcoding of data on both upstream and downstream traffic to present web information to the mobile user according to the QoS parameters set by the user. Active transcoding is defined as modifying the HTTP stream in situ, and it is entirely transparent to the user. Further, our system does not pose any additional requirements on the mobile user. This is an improvement over other proxy based systems, which only transcode images on the downstream and are mostly not configurable. While developed for mobile users, such a system can actually be useful in any low bandwidth scenario.
2954113
Tree Adjunct Grammars
In this paper, a tree generating system called a tree adjunct grammar is described and its formal properties are studied relating them to the tree generating systems of Brainerd (Information and Control14 (1969), 217-231) and Rounds (Mathematical Systems Theory 4 (1970), 257-287) and to the recognizable sets and local sets discussed by Thatcher (Journal of Computer and System Sciences1 (1967), 317-322; 4 (1970), 339-367) and Rounds. Linguistic relevance of these systems has been briefly discussed also.
41591052
A Tree Generating System
7243331
Using location information for scheduling in 802.15.3 MAC
In recent years, UWB has received much attention as a suitable physical layer (PHY) for wireless personal area networks (WPANS). UWB allows for low cost, low power, high bandwidth, short reach communication well suited for personal operating spaces. One of the key features offered by UWB is very accurate ranging between a transmitter/receiver pair. The IEEE 802.15.3 is a MAC protocol that has been proposed for WPANs. In this MAC, a combination of CSMA/CA and TDMA is used to achieve channel scheduling. The TDMA component ensures only one transmitter/receiver pair within a piconet is active at any given time thereby ensuring an exclusion region that covers the whole piconet. In this paper, we propose a less stringent scheduling mechanism that allows for concurrent communication between UWB transmitter/receiver pairs within a piconet. Exclusion is necessary only when the communicating entities are close enough such that interference between them would adversely affect successful reception of data at the receivers. The piconet coordinator (PNC) uses the ranging information provided by UWB to accurately position transmitters and receivers. The PNC schedules parallel transmissions between distinct transmit/receive pairs as long as they do not interfere. We present the results of our simulations of our proposed modifications and show that the network throughput can be significantly increased with very little change to the 802.15.3 MAC.