Good test collections, coupled with good evaluation metrics, are very useful for evaluating Information Access systems efficiently. But useful to whom? The in vitro (or Cranfield) evaluation paradigm has been criticised, mainly because of the absence of the user. On the other hand, user-in-the-loop evaluations are expensive, unrepeatable and often inconclusive. In light of this, we propose a ne...

Required capacity may be used in Connection Admission Control, Network Resource Management or for purposes of planning and dimensioning. From the well-known loss probability formula for the buuerless uid ow model, an implicit formula for the required capacity for a given QoS per connection may be derived which turns into a closed formula when it is evaluated in a special way. This formula, whos...

This paper presents simulation results on the performance of the network layer routing protocol CL in the Access network of UMTS. The network is modeled by a rooted-tree queuing system.

in MBS Dietmar Petras Dept. of Communication Networks, Aachen Univ. of Technology EMail: [email protected], WWW: http://www.dfv.rwth-aachen.de Abstract: This paper presents investigations on a medium access control protocol enabling transparent ATM access to mobile users. The Dynamic Slot Assignment protocol has been developed. The results of performance evaluations and improvements of ...

In this paper, we present a low latency media access control scheme which we call LLMAC (Low Latency MAC) for event-driven wireless sensor networks (WSN). In this kind of WSN, sensors do not regularly send data to the sink. They send a burst data only when there is an event in the monitoring area. It takes time for this burst data to arrive to the sink. Normally, these events are critical and w...

This paper describes SIMPLE: a performance evaluation tool environment for parallel and distributed systems based on monitoring of concurrent interdependent activities. We emphasize the tool environment as a prerequisite for successful performance evaluation. All tools use the data access interface TDL/POET which can decode measured data of arbitrary structure, format and representation. This m...

Buzz-net is a local network supported by a pair of unidirectional buses to which stations are connected via passive interfaces. The access protocol is a hybrid which combines random access and virtual token features. More precisely, the network operates in random access mode at light load and virtual token mode at heavy load. Because of the virtual token implementation, Buzz-net retains high ef...