Design Experience with an Integrated Testbed for Wireless Multimedia Computing

1999

IEEE Pers. Commun.

Current wireless terminals are limited to voice terminals such as cellular and PCS phones, and traditional laptop computers and PDAs configured with wireless modems and network interface cards. However, the current wireless networks, which are by and large wireless extensions of the circuit-switched voice networks, are being replaced by emerging wireless networking technologies that are intrinsically designed to support packet data and multimedia services. This will lead to novel networked applications and services, which in turn will require wireless terminals capable of exploiting these services. What shape will these next-generation wireless terminals take? The answer, based on the much talked about notion of "convergence," would appear to be a marriage of the laptop or PC with a wireless phone in the same package, leading to terminals such as the Nokia 9000 [1] or Bell Laboratories' wireless handset [2]. We argue that such a complex one-size-fits-all voice-data integrated wireless terminal will, at best, be a point solution. Rather, with the availability of cheap radio and computing hardware and ubiquitous low-cost indoor and outdoor wireless networking infrastructures, the capability to access a wireless network will soon be embedded into a variety of devices, gadgets, and appliances with specialized functions in our environment. In this article we describe the technological challenges and identify potential solutions in designing these myriad future "wireless terminals" that will handle diverse data types, have limited battery resources, and operate in environments that are unplanned, insecure, and time-varying, and have context-dependent services.

Section: I/o-centric Instead Of Cpu-centricmentioning

confidence: 99%

Advances in wireless terminals

Lettieri

1999

IEEE Pers. Commun.

“…A significant number of packets are processed in a simple manner and forwarded to the next hop. For the sake of overall delay and power consumption these packets should be processed as near to the radio hardware as possible [1]. To show this we measured the percentage of received packets (both routing and data from all the nodes) that were accepted, dropped or forwarded for a specific scenario simulated on the NS-2 network simulator.…”

Section: Introductionmentioning

confidence: 99%

Architecture strategies for energy-efficient packet forwarding in wireless sensor networks

Tsiatsis

Zimbeck

Proceedings of the 2001 International Symposium on Low Power Electronics and Design - ISLPED '01

2001

Self Cite

The energy-efficient communication among wireless sensor nodes determines the lifetime of a sensor network and exhibits patterns highly dependable on the sensor application and networking software. This software is responsible for processing the sensor data and disseminating the data to other nodes or a central repository. In this paper we propose a node architecture that takes advantage of both the intelligence of the radio hardware and the needs of applications to efficiently handle the packet forwarding. It exploits principles widely used in modern firewall network architectures and as our analysis shows achieves considerable energy savings. KeywordsEnergy-efficient packet forwarding, sensor networks

“…More recently, it has also been shown that significant improvements in throughput can result from letting the higher layers control radio parameters such as the processing gain [8], [9] when an increase in channel interference is indicated by throughput degradation. However, current commercial radios support limited dynamic adaptation.…”

mentioning

confidence: 99%

Adaptive radio for multimedia wireless links

Chien

IEEE J. Select. Areas Commun.

Jain

et al. 1999

The quality of wireless links suffers from timevarying channel degradations such as interference, flat-fading, and frequency-selective fading. Current radios are limited in their ability to adapt to these channel variations because they are designed with fixed values for most system parameters such as frame length, error control, and processing gain. The values for these parameters are usually a compromise between the requirements for worst-case channel conditions and the need for low implementation cost. Therefore, in benign channel conditions these commercial radios can consume more battery energy than needed to maintain a desired link quality, while in a severely degraded channel they can consume energy without providing any quality-of-service (QoS). While techniques for adapting radio parameters to channel variations have been studied to improve link performance, in this paper they are applied to minimize battery energy. Specifically, an adaptive radio is being designed that adapts the frame length, error control, processing gain, and equalization to different channel conditions, while minimizing battery energy consumption. Experimental measurements and simulation results are presented in this paper to illustrate the adaptive radio's energy savings.