Information Technology Reference
In-Depth Information
Chapter 3
E
RROR
C
ONTROL
S
CHEMES
FOR
B
LUETOOTH
T
ECHNOLOGY
:
A
NALYSIS AND
P
ERFORMANCE
João Henrique Kleinschmidt
1
Federal University of ABC, Santo André, Brazil
A
BSTRACT
This chapter presents different error control schemes of Bluetooth technology,
including the standard error control schemes and custom and adaptive error control
strategies proposed in the literature. Bluetooth provides an asynchronous connection-less
(ACL) link for data transmission. Bluetooth v2.0 with Enhanced Data Rate (EDR)
specification offers three transmission rates, which are basic rate of 1 Mbps (types of
DHx and DMx), enhanced data rates of 2 Mbps (EDR2, type of 2-DHx) and 3 Mbps
(EDR3, type of 3-DHx). Bluetooth employs stop and wait ARQ (Automatic Repeat
Request), CRC (Cyclic Redundancy Check) and FEC (Forward Error Correction). The
payload contains a header of 1 or 2 bytes and a 2-byte cyclic redundancy code (CRC) for
checking the integrity of the field after decoding. In DM (Data-Medium rate) packets the
payload is encoded with a (15, 10) shortened Hamming code capable of correcting single
bit error in each block. Only one fixed packet type is used during the whole Bluetooth
transmission period. These characteristics directly affect the throughput and energy
efficiency of a Bluetooth network. The choice of the best packet to be used in a
transmission depends of the channel conditions. This chapter describes and analyzes
some adaptive schemes proposed in the literature for this purpose. Other issue studied by
researchers is to apply different FEC schemes in the Bluetooth packets. Some of recent
proposals are described in this paper. An analytical framework is presented to analyze the
performance of error control schemes. Performance results are obtained through analysis
and simulation in Nakagami-m fading channels, indicating the best scheme for each
condition.
