Part 1 of a 6-part series of chapters on the subject of antenna theory and electro-magnetic propagation.
An introduction Bluetooth Smart by Paul Williamson, CSR
This whitepaper introduces the reader to an entirely new scheme for lossless audio compression called aptX Lossless. Briefly and simply, by employing dynamic adaptation techniques to a greater and more intelligent extent than conventional schemes, aptX Lossless, offers significant benefits over existing lossless audio codecs, and attains better coding scalability and run-time trade-offs as a result. These benefits are of considerable importance to strongly emerging applications for high-definition forms of digital entertainment, especially those deployed in the wirelessly networked, broadband home, and those portable systems being developed for consumers on the move.
CSR is a member of the Cambridge White Spaces Consortium that has set up a TV White Spaces Trial to determine if new unlicensed services could coexist with incumbent licensed services such as DTT and PMSE. This report specifically addresses PMSE with the Neul WhiteSpace devices (WSD) using the Weightless specification.
This paper was presented at the IWPC Workshop held in May 2011: 60 GHz Short Range Wireless – What is the Future? It was presented in the Session: Key Technologies, Enablers and Challenges - Devices by Rainer Herberholz.
Despite advances in voice and data communications in other domains, sound production for live events (concerts, theatre, conferences, sports, worship, etc) still largely depends on spectrum-inefficient forms of analogue wireless microphone technology. In these live scenarios, low-latency transmission of high-quality audio is mission critical. However, while demand increases for wireless audio channels (for microphones, in-ear monitoring and talkback systems), some of the radio bands available for “Programme Making and Special Events” are to be re-assigned for new wireless mobile telephony and Internet connectivity services: the FCC recently decided to permit so-called White Space Devices to operate in sections of UHF spectrum previously reserved for shared use by analogue TV and wireless microphones. This paper examines the key performance aspects of low bit rate audio codecs for the next generation of bandwidth-efficient digital wireless microphone systems that meet the future needs of live events.
One of the many advantages of HDTV is the ability to broadcast multi-channel audio and allow listeners to immerse themselves in a true surround-sound experience. However, it would be true to say that the audio portion in HDTV has been the poor relation when compared to the video component. Further development in video is slowing and suffering from the laws of diminishing returns with regards to engineering input versus return on investment. In contrast, the audio component is virtually a virgin territory as can be witnessed by the limited number of options currently available for broadcast, acquisition, production and processing.
The delivery of multi-channel audio – from mono to surround sound – in real-time over public IP networks for the purpose of interactive crowd-participant gaming presents a significant design engineering challenge to games developers, console manufacturers, ISPs and CDNs. Leveraging expertise gained in professional broadcasting and recording studio post-production, APT has developed a robust and scalable audio codec technology that meshes with popular gaming systems to realize low-latency distribution of high-quality audio for immersive, instantaneous audio experiences in massively multi-player online games involving interactive audience responses.