wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

49-2 Industrial Communication Systems
In 1998, Ericsson, Nokia, IBM, Toshiba, and Intel founded the Bluetooth Special Interest Group (SIG)
to work out a standard and to promote the technology. The first standard was published as Version 1.0a
in July 1999. Version 1.0b followed in December of the same year. Only in February 2001, was the standard
of Version V1.1 presented, which was considered the first reliable standard on which companies
could build products in line with the market, as the previous standards had significant flaws and inaccuracies.
Of late, the standard has come to be known as the IEEE 802.15.1 short-range communication.
Bluetooth devices communicate as short-range devices (1–100.m) in the license-free ISM band at
2.4–2.4835.GHz. It uses a radio technology called the frequency-hopping spread spectrum. The initial
data rate was specified at 1.Mbps, but the newest enhanced data rate specifications achieve up to 3.Mbps.
Bluetooth defines not only a radio but also a protocol stack with profiles. Profiles define the capabilities
and the usage scenarios devices have to implement in order to be interoperable with other devices
supporting the same profile. With certification required for any Bluetooth device, interoperability shall
be guaranteed. However, as it has been shown in practice, consumers have also experienced many problems
with certified devices in the past.
49.1.2 Bluetooth Specifications
The specification process is an ongoing process where features are improved while continuing to maintain
backward compatibility with previous specifications.
49.1.2.1 Bluetooth 1.0 and 1.0B
These initial versions never got out into the market in significant numbers as the releases had several
problems for vendors in developing interoperable devices. A mandatory Bluetooth device hardware
address (BD_ADDR) was included while connecting the devices, which proved to be a set back for
various Bluetooth planned services.
49.1.2.2 Bluetooth 1.1
Various errors were removed from the previous release. The Bluetooth 1.1 short-range technology was
standardized as the IEEE 802.15.1-2002. Additionally, features of support for the nonencrypted channels
and the Received Signal Strength Indicator (RSSI) were added.
49.1.2.3 Bluetooth 1.2
Users of Bluetooth 1.1 were confronted with interference problems with Wireless LAN devices and experienced
long connection set-up times that had to be reduced. The key features of the release are as follows:
• An adaptive frequency-hopping spread spectrum, to avoid using occupied frequency channels
• A higher effective data throughput, up to 721.kbps
• Extended Synchronous Connections (eSCO) that increase latency for concurrent audio data
transfer, improve the voice quality of audio links, and allow retransmissions of corrupted packets
• The previous standard was upgraded as the IEEE 802.15.1-2005
49.1.2.4 Bluetooth 2.0 + EDR
Besides some modifications and fixing of errors in the previous release, this specification introduced
the optional enhanced data rate (EDR) for faster data transfer, which was 3.Mbps. The EDR provides the
following features:
• Three times faster transmission speed, up to (2.1.Mbps); hence, high quality audio links were
possible
• Backward compatibility to the V1.x specifications by allowing simultaneous EDR and non-EDR
connections
• Lower power consumption due to a reduced duty-cycle capability
© 2011 by Taylor and Francis Group, LLC