Bluetooth low energy host tws mini bluetooth speaker

Hosts are the unsung heroes of the Bluetooth world. Hosts contain multiplexing layers, protocols, and procedures for implementing many useful and interesting processes. The host is built on the upper part of the host controller interface, which is a multiplexing layer of the Logical Link Control and Adaptation Protocol (L2CAP). On top of it are the two basic building blocks of the system: the security manager (which handles all things like authentication and secure connections) and the property protocol (which exposes state data on the device). Above the attribute protocol is a generic attribute specification that defines how the attribute protocol implements reusable services that expose standard features of the device. Finally, the Universal Access Specification defines how devices can find and connect with each other in an interactive way. The host does not explicitly specify its upper-layer interface. Each operating system or environment exposes the host's API in a different way, whether through a functional interface or an object-oriented interface. www.bjbjaudio.com    <a style="opacity:0.0;color:#ffffff">tws mini bluetooth speaker</a>       <a style="opacity:0.0;color:#ffffff">tws mini bluetooth speaker</a>

Logical Link Control and Adaptation Protocol
The Logical Link Control and Adaptation Protocol (L2CAP) is the multiplexing layer of Bluetooth Low Energy. This layer defines two basic concepts: L2CAP channel and L2CAP signaling. The L2CAP channel is a bidirectional data channel leading to a specific protocol or specification on the peer device. Each channel is independent and can have its own flow control and configuration information associated with it. Classic Bluetooth uses most of the features of L2CAP, including dynamic channel identifiers, protocol service multiplexers, enhanced retransmission, streaming mode, and more. In contrast, Bluetooth Low Energy uses only minimal L2CAP functionality. Only fixed channels are used in Bluetooth Low Energy: one for the signaling channel, one for the security manager, and one for the attribute protocol. Bluetooth Low Energy has only one frame format, the B frame, which contains a two-byte length field and a two-byte channel identifier field, as shown in Figure 3-3. The format of the B frame is the same as the basic frame format used by traditional L2CAP on each channel. Before negotiating to use some more complex frame formats, traditional L2CAP will always use this frame format. An example of a complex frame format is the classic Bluetooth frame that includes additional frame sequences and check values. These frames are not necessary in Bluetooth Low Energy because the link layer already has enough check strength to use additional check values, and the simple attribute protocol does not send messages out of sequence with multiple channels. By keeping the protocol simple and performing just the right checks, only one frame format is sufficient. www.bjbjaudio.com       <a style="opacity:0.0;color:#ffffff">tws mini bluetooth speaker</a>      <a style="opacity:0.0;color:#ffffff">tws mini bluetooth speaker</a>

Security Manager Protocol
The security manager defines a simple pairing and key distribution protocol. Pairing is a process of obtaining the trust of the other party's device, which is usually implemented by means of authentication. After pairing, the link encryption and key distribution process follows. The slave device shares the secret to the master device during key distribution, and when the two devices reconnect at some point in the future, they can encrypt using the previously distributed shared secret to quickly authenticate each other's identities. The security manager also provides a security toolbox responsible for generating hashes of the data, confirmation values, and short-lived keys used in the pairing process. www.bjbjaudio.com         <a style="opacity:0.0;color:#ffffff">tws mini bluetooth speaker</a>