Chapter 7: Wireless Services Part 1: Bluetooth

1. Chapter 7:Wireless ServicesPart 1: Bluetooth Computer Data Communications

2. Types of Wireless Networks

3. Benefits of Wireless Network • Mobility • Provide users with access to real-time information anywhere in their organization. • Installation Speed and Simplicity • Installing a wireless system can be fast and easy and can eliminate the need to pull cable through walls and ceilings • Eliminate wiring costs • Expensive, unattractive to wire and re-wire existing homes

4. Benefits of Wireless Network • Flexible configuration of networks • Easy relocation and modification to network structures • Peer to peer network or infrastructure • Scalability • Can easily scale to large installation that enable roaming over broad area.

5. Bluetooth • Bluetooth is a Radio Frequency (RF) specification for short-range, point-to-multipoint voice and data transfer. • Always-on, short-range radio hookup that resides on a microchip. • Can transmit through solid, non-metal objects. • Low-power short-range wireless standard for a wide range of devices • Nominal link range from 10 cm to 10m, but can extended to 100m by increasing transmit power

6. Bluetooth • Two Bluetooth devices within 10 m of each other can share up to 720 kbps of capacity • Uses 2.4-GHz band (available globally for unlicensed low-power uses) • Facilitates adhoc connections for stationary and mobile communications.

7. Examples of Bluetooth Capability • Make calls from a wireless headset connected remotely to a cell phone • Eliminate cables linking computers to printers, keyboards, and the mouse • Hook up MP3 players wirelessly to other machines to download music • Set up home networks to remotely monitor air conditioning, appliances, and Internet surfing • Call home from a remote location to turn appliances on and off, set the alarm, and monitor activity.

8. Bluetooth Applications • Up to eight devices can communicate in a small network called a piconet; ten of these can coexist in the same coverage range of the Bluetooth radio. • Bluetooth provides for three general application areas short-range wireless connectivity: • Data and voice access points • Cable replacement • Ad hoc networking

9. Bluetooth Applications • Data and voice access points • Bluetooth facilitates real-time voice and data transmissions by providing effortless wireless connection of portable and stationary communications devices. • Cable replacement • Bluetooth eliminates the need for numerous, often proprietary, cable attachments for connection of practically any kind of communication device. Connections are instant and are maintained even when devices are not within line of sight. The range of each radio is approximately 10m but can be extended to 100m by increasing transmit power.

10. Bluetooth Applications • Adhoc networking • A device equipped with a Bluetooth radio can establish instant connection to another Bluetooth radio as soon as it comes into range.

11. Bluetooth Vision

12. Bluetooth Standards Documents • The Blue standards documents are divided into two groups: core and profile specifications. • Core Specifications • Describes layers of the protocol architecture, from radio interface to link control • Profile Specifications • Discusses the use of the technology defined in the core specifications to implement a particular usage model • General access profile specifies how the baseband architecture should be used between devices that implement one or multiple profiles • Other profiles fall into one of two categories: cable replacement or wireless audio

13. Bluetooth Protocol Stack

14. Bluetooth Protocol Architecture • Bluetooth is defined as layered protocol architecture consisting of: • Core protocols • The core protocols form a five layer stack consisting of the following elements: • Radio, Baseband, Link Manager Protocol (LMP), Logical link control and adaptation protocol (L2CAP), Service discovery protocol (SDP). • Cable replacement protocols (RFCOMM) • presents a virtual serial port that is designed to make replacement of cable technologies as transparent as possible

15. Bluetooth Protocol Architecture • Telephony Control Protocol (TCS BIN) • a bit-oriented protocol that defines the call control signaling for the establishment of speech and data calls between Bluetooth devices

16. Bluetooth Protocol Architecture • Adopted Protocols • The adopted protocols are defined in specifications issued by other standards-making organizations and incorporated into the overall Bluetooth archictecture. The Bluetooth strategy is to invent only necessary protocols and use existing standards whenever possible. • The adopted protocol includes the following: • PPP: The point-to-point protocol is an Internet Standard protocol for transporting IP datagrams over a point-to-point link • TCP/UDP/IP: These are foundation protocols of TCP/IP protocol suite.

17. Bluetooth Protocol Architecture • Adopted Protocols • The adopted protocol includes the following: • WAE/WAP: Bluetooth incorporates the wireless application environment and the wireless application protocol into its archictecture. • OBEX: The object exchange protocol is a session-level protocol developed by the Infrared Data Association for the exchange of objects. OBEX provides functionality similar to that of HTTP but a simpler fashion. It also provides a model for representing objects and operations. Examples of content formats by OBEX are vCard and vCalendar, which provide the format of an electronic business card and personal calendar entries and scheduling information, respectively.

18. Bluetooth Core Protocols • The core protocols form a five-layer stack consisting of the following elements: • Radio: Specifies details of the interface, including frequency, the use of frequency hopping, modulation scheme and transmit power. • Baseband: Concerned with the connection establishment within a piconet, addressing, packet format, timing and power control.

19. Bluetooth Core Protocols • The core protocols form a five-layer stack consisting of the following elements: • Link manager protocol (LMP) : Responsible for link setup between Bluetooth devices and ongoing link management. This is includes security aspects such as authentication and encryption, plus the control and negotiation of baseband packet sizes. • Logical link control and adaptation protocol (L2CAP) : Adapts upper-layer protocols to the baseband layer. L2CAPS provides both connectionless and connection-oriented.

20. Bluetooth Core Protocols • The core protocols form a five-layer stack consisting of the following elements: • Service discovery protocol (SDP) : Device information, services and the characteristics of the services can queried to enable the establishment of a connection between two or more Bluetooth devices..

21. Bluetooth Core Protocols : - Bluetooth Radio • Frequency 2.4 GHz (ISM band) • Time Division Duplex (TDD) • 79 (or 23) channels, 1 MHz spacing • Frequency hopping, peak Tx power 20 dBm • 1 Mbps gross data rate ( 432.6 kbps sym. / 721 – 57.6 kbps asym) • CVSD voice encoding – 64 kbps

22. Bluetooth Core Protocols : -Bluetooth Baseband • Piconet • 2 or more Bluetooth units sharing a channel (hopping) form a piconet • Connected units can be master or slave. Master is the device that initiates the formation of piconet. • Master can connect to maximum 7 slaves per piconet simultaneously. • In forming a piconet, master gives slaves its clock and device ID. • Unique hopping pattern for each piconet • All devices in a piconet hop together. • Each piconet has a maximum total capacity of 1 Mbps.

23. Bluetooth Core Protocols : -Bluetooth Baseband • Piconet

24. Bluetooth Core Protocols: -Bluetooth Baseband • Scatternet • When 2 or more piconets partially overlap in time and space, a scatternet is formed. • Each piconet has a single master and a set of slaves. A slave can participate in more than one piconet by in turn establishing connections with and synchronizing to different masters in proximity. A single device can act as a slave in one piconet but assume the role of master in another piconet.

25. Bluetooth Core Protocols:-Bluetooth Baseband • Scatternet • The scatter topology provides a flexible method by which devices maintain multiple connections. This could be especially useful for mobile devices which frequently move into and out of proximity to the other devices.

26. Bluetooth Baseband:- Piconets and Scatternets

27. Bluetooth Baseband:- Operational States

28. Bluetooth High-Priority Usage Models • File Transfer • Internet Bridge • LAN Access • Synchronization • Three-in-one Phone • Headset

29. Bluetooth Product • Palm Bluetooth SD Card • Nokia 7650 • Ericsson T68i • Compaq iPaq H3870 • Sony Ericsson Headset • Sony Vaio SRX-51P • Hp 995c Bluetooth Printer

30. Competing Technologies • IrDA • Inexpensive but • Requires direct line-of-sight • Limited to point-to-point connections • Limited range • IEE802.11 • Higher transmission capacity • Number of simultaneous users is higher but • Hardware size is bigger • Module is more expensive

31. Competing Technologies • Home RF • Wireless technology optimized for the home environment • Open industry specification for wireless digital communication between PCs & consumer electronic devices anywhere in and around • Support more units per net • Just 50 frequency hops per second