Tip & How-To about Electronics - Others
Any Bluetooth device can be a master or a slave, depending on the application scenario.
Bluetooth employs frequency hopping spread spectrum (FHSS) to communicate. So in order
for multiple Bluetooth devices to communicate, they must all synchronize to the same
hopping sequence. The master sets the hopping sequence, and the slaves synchronize to the
A piconet is formed by a master and up to seven active slaves. The slaves in a piconet only
communicate with the master.
A scatter net can be formed by linking two or more piconets. When a device is present in
more than one piconet, it must time-share and synchronize to the master of the piconet with
which it is currently communicating.
While the topology and hierarchical structure of WLAN networks are relatively simple,
Bluetooth networks are far more diverse and dynamic. They are constantly being formed,
modified, and dissolved, as Bluetooth devices move in and out of range of one another. And
because different Bluetooth devices can represent many different usage profiles, there are
many different ways in which Bluetooth devices can interact.
The concept of service discovery is utilized to determine what kind of Bluetooth devices are
present and what services they desire or offer. When a Bluetooth device requires a service, it
begins a discovery process by sending out a query for other Bluetooth devices and the
information needed to establish a connection with them. Once other Bluetooth devices are
found and communication is established, the Service Discovery Protocol (SDP) is utilized to
determine what services are supported and what kinds of connections should be made.
In order for the above to happen, devices willing to connect must be located. Some devices
may be set up so that they are invisible. In this case, they can scan for other Bluetooth
devices, but will not respond if they are likewise queried. Applications determine whether a
device is connectable or discoverable, and thus applications determine the topologies of
networks and their internal hierarchies.
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Nov 27, 2016 | Panasonic Audio Players & Recorders
Dec 06, 2014 | Microsoft Computers & Internet
Bluetooth uses a technique called spread-spectrum frequency hopping. It changes frequencies 1,600 times every second. A frequency of 2.45 gigahertz (actually between 2.402 GHz and 2.480 GHz, to be exact). For the bluetooth device to work at 100% it needs to be 100% compatiable. More than likely, if you change your earpiece device, you should be able to pickup your songs. If you go to the VerizonWireless website, they should have 100% compatiable devices.
Why is it called Bluetooth?
Harald Bluetooth was king of Denmark in the late 900s. He managed to unite Denmark and part of Norway into a single kingdom then introduced Christianity into Denmark. He left a large monument, the Jelling rune stone, in memory of his parents. He was killed in 986 during a battle with his son, Svend Forkbeard. Choosing this name for the standard indicates how important companies from the Nordic region (nations including Denmark, Sweden, Norway and Finland) are to the communications industry, even if it says little about the way the technology works.
Oct 20, 2007 | Motorola Mobility RAZR V3i Cellular Phone
Aug 03, 2006 | Lantronix (200.2071)
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