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Piconet Establishment and Operation in .NET Development Code 128B in .NET Piconet Establishment and Operation

8.4.2.2 Piconet Establishment and Operation use visual .net code-128c development togenerate code 128 code set b in .net Typical 2D QR Code The piconet is governed ent code-128b for .NET irely by its master. The master"s address determines the frequency hopping sequence and the channel access code (the code that uniquely identifies the piconet).

Since Bluetooth is based on TDD, every Bluetooth station has an internal system clock which determines the timing and hopping of the radio transceiver. This clock has no relation to the time of day and can therefore be initialized at any value, does not require adjustments, and is never turned off. For synchronization with other units, only offsets are used and added to the native internal clock.

To ensure synchronization, the master sets the timing of all slaves based on its clock by transmitting to the slaves its clock reading. The slaves add an offset value to their native clocks so they can be synchronized to the master clock. Since the clocks are freerunning, the offsets have to be updated regularly.

Establishing piconet is controlled by link control state. Figure 8.14 shows the piconet establishment sequence.

. Figure 8.14. Piconet Establishment Sequences First, the master executes ANSI/AIM Code 128 for .NET the inquiry process to obtain the device addresses and clocks of the slaves within the transmission coverage. Then, the master performs the paging process to establish the connections with the specific slave.

Finally, both the master and the active slaves can communicate with each other.. 8.4.2.3 Scatternet Establishment and Operation To increase the coverage ar .net vs 2010 code 128a ea and the number of supported stations, several piconets may coexist in the same area. Each piconet"s master specifies a different hopping series.

In addition, the packets carried on the channels are preceded by different channel access codes as determined by the master addresses. As the number of coexisting piconets increases, the probability of collisions increases since different piconets may transmit on one of the 79 frequency channels. If several piconets coexist in the same area, a station can participate in two or more piconets by applying time multiplexing.

In each piconet, the station will use this piconet hopping series, master device address, and proper clock offset. A Bluetooth station can act as a slave in several piconets but as a master in only one piconet. A group of connected piconets is referred to as a scatternet.

Stations must use time multiplexing to switch between the piconets in which they participate. In case of ACL links, a station can request to enter the Hold or Park mode so that during this. mode it can join the other piconet. Units in the Sniff mode may have sufficient time to visit another piconet between the sniff slots. If SCO links are established, other piconets can only be visited in the non-reserved slots between the sniff slots.

Since coexisting piconets do not have a mechanism to synchronize clocks, additional guard time should be considered for proper switching. A master can become a slave in another piconet by being paged by the master of this other piconet. On the other hand, a slave participating in one piconet can be a master in another piconet.

Since the paging unit always starts out as master, a master-slave role exchange will be required. Such an exchange may involve a reorganization of piconets since slaves may change from the current master to the new master. This is a complex process since it requires all stations to resynchronize their clocks, transit to the frequency hopping series of the new masters, and adjust to the new master device addresses.

This reorganization of piconets should be done without interfering with ongoing communication activities and without involving the users. The option of setting up a completely new set of piconets will require a long period of time. Another option is to have the new masters utilize their knowledge of timing and hopping sequences to reduce the time for such an exchange.

Because of the complexity of the piconet reorganization process, it is currently left outside the scope of the Bluetooth standard. Therefore, Bluetooth developers need to design and implement their own exchange algorithm..

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