Technologies for DVB Services on the Internet

In 2004 DVB approved the first edition of the DVB IP Handbook, intended to support the first commercial deployments of Internet TV services. The specifications in the handbook standardize technologies at the receiver interface, to enable TV, radio, and general interactive multimedia services over IP-based networks. This paper gives an overview of the specifications, beginning with the reference architecture currently used by DVB. The key technologies specified are service discovery and selection, a DVB Real-Time Streaming Protocol client, MPEG-2 transport over IP, IP address allocation and network time services, receiver identification, and a network provisioning option.     

Iterative multiuser turbo-code receiver for DS-CDMA

A number of different iterative decoding methods are proposed for multiuser interference cancellation in a code-division multiple-access system where turbo-codes are utilized for forward error correction (FEC). The individual users are decoded separately with the operation of iterative interference cancellation being mixed with iterative decoding of the turbo-code. This results in a modest increase in the overall complexity as compared to a conventional single-user receiver utilizing turbo-code for FEC. Numerical results are presented showing that the proposed iterative decoders show an improvement in the bit error rate performance and/or a reduction in the computational complexity as compared to similar previously known methods reported by M.C. Reed et al. (see 8th IEEE Int. Symp. Personal, Indoor and Mobile Radio Commun. - PIMRC'97, vol.2, p.740-4, 1997; IEEE Trans. Commun., vol.46, p.1693-9, 1998).     

Spinal anaesthesia with 0.5% hyperbaric bupivacaine in elderly patients: effect of site of injection on spread of analgesia

In this randomized, observer-blind study, we have examined, in elderly patients, the effect of site of injection on analgesia levels after spinal injection of 0.5% hyperbaric bupivacaine solution. Thirty male patients, aged 68-87 yr, undergoing minor urological surgery during spinal anaesthesia received 3 ml of a 0.5% hyperbaric bupivacaine solution at either the L3-4 (n = 15) or L4-5 (n = 15) interspace. The solution was injected with the patient in the sitting position. The patient remained sitting for 2 min and was then placed in the supine horizontal position. Analgesia levels were assessed bilaterally using pin-prick. The highest analgesia levels did not differ between groups (medians were approximately T7). There were no significant differences in the time to maximum cephalad spread of analgesia, maximum degree of motor block or haemodynamic changes. We conclude that injection at the L4-5 interspace has no advantage compared with injection at the L3-4 interspace.     

Easy doesn’t do it: skill and expression in tangible aesthetics

In this paper, we articulate the role of movement within a perceptual-motor view of tangible interaction. We argue that the history of human–product interaction design has exhibited an increasing neglect of the intrinsic importance of movement. On one hand, human–product interaction design has shown little appreciation in practice of the centrality of our bodily engagement in the world. This has resulted in technologies that continue to place demands on our cognitive abilities, and deny us the opportunity of building bodily skill. On the other hand, the potential for movement in products to be a meaningful component of our interaction with them has also been ignored. Both of these directions (design for bodily engagement and the expressiveness of product movements) are sketched out, paying particular respect for their potential to impact both interaction aesthetics and usability. We illustrate a number of these ideas with examples.