USB for Audio There also several USB Audio

USB for Audio There also several USB Audio chips. You install a custom driver on the host computer, and the USB sound device appears as a Windows (or Linux, or Mac) sound device. The downside of this is that you have to do this install for every device you might use the USB sound device with. C-media single chip USB Audio system

Bluetooth is a wireless cable replacement standard. After a slow start, Bluetooth technology is taking off. Sales for 2005 should exceed 200 million units, and is roughly doubling each year. Bluetooth comes in two flavors: Class 2: for personal devices or in-vehicle use, around 10 -20 m (try 10 -20 feet in practice) Class 1: For longer range up to 100 m, e. g. in a household or office.

Bluetooth Data Rates Bluetooth also comes in two versions. Version 1 (usually you see 1. 1 or 1. 2) has data rates up to 723 kb/s. Version 2 (aka EDR or Extended Data Rate) triples the data rate up to about 2 Mb/s. Bluetooth shares the 2. 4 GHz spectrum with Wi. Fi (802. 11 a, b, g etc. ).

Bluetooth Profiles One of the most useful innovations in the Bluetooth standard is the use of device profiles. A profile is an abstract device spec. that has to be supported at both ends of a connection. If you like, it’s the kind of cable(s) that Bluetooth connection supports. Each connection can support several profiles at once. Profiles eliminate the need for custom drivers on the host, and allows a Bluetooth device to connect to any host (PC, PDA, cell phone) that supports the profile(s) it uses.

Bluetooth Profiles

Bluetooth Chips - CSR Cambridge Scientific Radio (CSR) manufactures a large number of Bluetooth chips, probably more than half of those shipped. This is a diagram of their Bluecore 2 series. This chip fits in a 1 cm 2 package

Developing with Bluetooth • The newest modules make it pretty easy to go wireless. Most modules can be used as serial cable replacements. • The next simplest step is to add a microprocessor to act as controller (PIC etc. ), using the module’s serial profile. But since new BT chips have a powerful, energy-efficient processor on-board already, this is rather wasteful. • You can develop for the native processor, but you will need to buy some expensive development tools. CSR and some module vendors provide virtual machines so your code can’t void the module’s qualification.

Semantic Web • Tim Berners-Lee originally expressed the vision of the semantic web as follows: • I have a dream for the Web [in which computers] become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers. A ‘Semantic Web’, which should make this possible, has yet to emerge, but when it does, the day-to-day mechanisms of trade, bureaucracy and our daily lives will be handled by machines talking to machines. The ‘intelligent agents’ people have touted for ages will finally materialize. – Tim Berners-Lee, 1999

• Humans are capable of using the Web to carry out tasks such as finding, reserving a library book, and searching for a low price for a DVD. However, a computer cannot accomplish the same tasks without human direction because web pages are designed to be read by people, not machines. The semantic web is a vision of information that is understandable by computers, so that they can perform more of the tedious work involved in finding, combining, and acting upon information on the web.

• The Semantic Web is an evolving development of the World Wide Web in which the meaning (semantics) of information and services on the web is defined, making it possible for the web to "understand" and satisfy the requests of people and machines to use the web content. It derives from World Wide Web Consortium director Sir Tim Berners-Lee's vision of the Web as a universal medium for data, information, and knowledge exchange.

• Some elements of the semantic web are expressed as prospective future possibilities Other elements are expressed in formal specifications. Including • Resource Description Framework (RDF), – Describes the data about resource – a variety of data interchange formats (e. g. RDF/XML, N 3, Turtle, N-Triples), and notations such as RDF Schema (RDFS) • The Web Ontology Language (OWL) • Describes the relationship between the data (Knowledge Domain) • Formal description of concepts, terms, and relationships within a given knowledge domain.

• The Resource Description Framework (RDF) is a family of World Wide Web Consortium (W 3 C) specifications originally designed as a metadata model. It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax formats.

• The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies, and is endorsed by the World Wide Web Consortium. This family of languages is based on two (largely, but not entirely, compatible) semantics: OWL DL and OWL Lite semantics are based on Description Logic, which have attractive and wellunderstood computational properties, while OWL Full uses a semantic model intended to provide compatibility with RDF Schema. OWL ontologies are most commonly serialized using RDF/XML syntax. OWL is considered one of the fundamental technologies underpinning the Semantic Web, and has attracted both academic and commercial interest.