The Development Of Bluetooth Technology

By Author: fed pats
Total Articles: 225
Comment this article

The convergence of computing and communications has led to the development of Bluetooth technology. Taking the short range wireless data usage to a new level, this technology is predicted to dominate both the home and business markets. Now no more complicated tangle of cables and wires are required to connect electronic equipment. A revolutionary technology called Bluetooth allows for the replacement of the cumbersome cables used today to connect a laptop to a cellular phone with one universal low-cost, short-range radio link. Printers, PDAs, desktops, fax machines, keyboards, and virtually any other digital device can be a part of the Bluetooth system. Bluetooth is faster than mobile phones, including the upcoming The SCO link is symmetric and typically supports time-bound voice traffic. SCO packets are transmitted over reserved intervals. Once the connection is established, both master and slave units may send SCO packets without being polled. One SCO packet type allows both voice and data transmission with only the data portion being retransmitted when corrupted. The ACL link is packet-oriented and supports both symmetric ...
... and asymmetric traffic. The master unit controls the link bandwidth and decides how much piconet bandwidth is given to each slave, and the symmetry of the traffic. Slaves must be polled before they can transmit data. The ACL link also supports broadcast messages from the master to all slaves in the piconet. The three error-correction schemes defined for Bluetooth baseband controllers include 1/3 rate forward error correction code (FEC), 2/3 rate forward error correction code (FEC), and automatic repeat request (ARQ) scheme for data. FEC scheme reduces the number of retransmissions in the data payload. However, in a reasonably error-free environment, F C creates unnecessary overhead that reduces the throughput. Since the packet header contains valuable link information and should survive bit errors, it is always protected by a 1/3 rate FEC. An unnumbered ARQ scheme is applied in which data transmitted in one slot is directly acknowledged by the recipient in the next slot. For a data transmission to be acknowledged, both the header error check and the cyclic redundancy check must be okay; otherwise a negat ve acknowledge is returned The Link Manager (LM) software carries out link setup, authentication, link configuration, and other protocols. It discovers other remote LMs and communicates with them via the Link Manager Protocol (LMP). To perform its service provider role, the LM uses the services of the Link Controller (LC). The LM offers services such as sending and receiving of data, link address inquiries, connection set-up, and authentication. It has an efficient means to inquire and report a name or device ID up to 16 characters in length. It negotiates on link mode and set-up. It decides the actual frame type on a packet by-packet basis. In sniff mode, the duty cycle of the slave is reduced: it listens only M slots where M is negotiated at the LM. The master can only start transmission in specified time slots spaced at regular intervals. In hold mode, turning off the receiver for longer periods saves power. Any device can wake up the link again, with an average latency of 4 seconds. This is defined by the LM and handled by the LC. The LM sets a device in park mode when it does not need to participate on the channel and wants to stay synchronised. It wakes up at regular intervals to listen to the channel in order to resynchronize with the rest of the piconet, and to check for page messages. Any device displaying the Bluetooth logo should interoperate with other Bluetooth devices. Software interoperability begins with the Bluetooth link level protocol, responsible for protocol multiplexing, device and service discovery, and segmentation and reassembly. Bluetooth devices must be able to recognize each other and load the appropriate software to discover the higher level abilities each device supports. Interoperability at the application level requires identical protocol stacks. Different Bluetooth devices (PCs, handhelds, headsets, cellular telephones) have different compliance requirements. To obtain more functionality, the Bluetooth software framework will reuse existing specifications such as OBEX, vCard/vCalendar, human interface device (HID), and TCP/IP. Device compliance requires conformance to both the Bluetooth specification and existing protocols. The software frame work is contemplating functions like configuration and diagnosis utility, device discovery, cable emulation, peripheral communication, audio communication and call control, object exchange for business cards and phone books, and networking protocol. The Bluetooth specification contemplates interfaces where the radio modules may be integrated into notebook personal computers or attached using PC-card or USB. Notebook PC usage models include remote networking using a Bluetooth cellular phone, speakerphone applications using a Bluetooth cellular phone, business card exchange between Bluetooth notebooks, handhelds, and phones, and calendar synchronisation between Bluetooth notebooks, handhelds, and phones. Bluetooth technology is operating system independent and not tied to any specific operating system. Implementations of the Bluetooth for several commercial operating systems are in development. For notebook computers, the implementation of the Bluetooth in Microsoft Windows 98 and NT 5.0 using WDM and NDIS drivers is being contemplated. Customer-visible interoperability is promoted by requiring minimal levels of software functionality, such as speakerphone, on notebook computers.Lucent technologies, Motorola, and 3Com have signed on as primary Bluetooth promoters. Many smaller companies worldwide have also signed up for royalty-free rights to the emerging standard.

Company: Toronto pcs

Address: 222 Spadina Avenue, Unit # 116 A Toronto, ON - M5T3B3

Zip code: M5T3B3

Contact person: Fedrick Patrick

Phone: 647-693-5036

Email: fed.pats@gmail.com

More information can be found online at: http://www.torontopcs.com