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.
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.
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.
2903570
Secure sensor networks for perimeter protection
Sensor networks have been identified as being useful in a variety of domains to include the battlefield and perimeter defense. We motivate the security problems that sensor networks face by developing a scenario representative of a large application class where these networks would be used in the future. We identify threats to this application class and propose a new lightweight security model that operates in the base station mode of sensor communication, where the security model is mindful of the resource constraints of sensor networks. Our application class requires mitigation against traffic analysis, hence we do not use any routing mechanisms, relying solely on broadcasts of end-to-end encrypted packets. Our model extends the broadcast range of the base station model by utilizing nodes adjacent to the base station as an intermediary hop. Additionally, our model detects and corrects some classes of aberrant node behavior. We have simulated our model and present simulation results.
16208693
Some results in tree automata
In this paper, we will essentially present three results in tree automata. Two of these are concerned with certain open problems posed by Rounds [1] and Martin and Vere [3], and the third one is related to the result of Peters and Ritchie [4].
 First we will briefly state the results and then describe them in some detail in Sections 2, 3, and 4.
3018861
Using peer-to-peer data routing for infrastructure-based wireless networks
A mobile ad-hoc network is an autonomous system of mobile routers that are self-organizing and completely decentralized with no requirements for dedicated infrastructure support. Wireless infrastructure in terms of base stations is often available in many popular areas offering highspeed data connectivity to a wired network. In this paper we describe an approach where infrastructure components utilize passing by mobile nodes to route data to other devices that are out of range. In our scheme, base stations track user mobility and determine data usage patterns of users as they pass by. Based on this, base stations predict the future data needs for a passing mobile device. These base stations then collaborate (over the wired network) to identify other mobile devices with spare capacity whose routes intersect that of a needy device and use these carriers to transport the needed data. When such a carrier meets a needy device, they form ad hoc peer-to-peer communities to transfer this data. In this paper, we describe the motivation behind our approach and the different component interactions. We present the results of simulation work that we have done to validate the viability of our approach. We also describe, Numi, our framework for supporting collaborative infrastructure and ad hoc computing along with a sample application built on top of this highlighting the benefits of our proposed approach.
6376128
Toward Distributed service discovery in pervasive computing environments
The paper proposes a novel distributed service discovery protocol for pervasive environments. The protocol is based on the concepts of peer-to-peer caching of service advertisements and group-based intelligent forwarding of service requests. It does not require a service to be registered with a registry or lookup server. Services are described using the Web Ontology Language (OWL). We exploit the semantic class/subClass hierarchy of OWL to describe service groups and use this semantic information to selectively forward service requests. OWL-based service description also enables increased flexibility in service matching. We present simulation results that show that our protocol achieves increased efficiency in discovering services (compared to traditional broadcast-based mechanisms) by efficiently utilizing bandwidth via controlled forwarding of service requests.