Patent Application
20120096186
This application claims the benefit of Taiwan application Serial No. 99135080, filed Oct. 14, 2010, the subject matter of which is incorporated herein by reference.
1. Field of the Invention
The invention relates in general to a method for signal synchronization and a device and a system using the same, and more particularly to a method for peer to peer (P2P) signal synchronization and P2P wireless communication device and system.
2. Description of the Related Art Internet and wireless communication have played very important roles in the life of the modern human beings. At present, interaction modes of each node over the Internet may be classified into: (1) client/server architecture; (2) peer to peer architecture; and (3) service-oriented architecture.
In the first architecture, a server has to be used and a network system has to be created in advance so that the network service can be used. In the second architecture, all the nodes over the network simultaneously play the roles of clients and servers, and any two nodes can directly share information or exchange contents without through the server. All the nodes may be potential users of the service or the potential providers of the service. So, the peer to peer architecture is adapted to the independent and open distributed Internet application system.
For the wireless communication, the P2P wireless communication technology, such as the bluetooth communication technology, has been widely applied to various modern portable electronic devices. The bluetooth communication technology is a short distance (10 m to 100 m) and low power wireless communication technology, and is adapted to the data exchange between various electronic devices in the small area environment, such as the environment at home, in the office and in the vehicle. It is an important subject in the industry to optimize the network architecture in conjunction with the P2P wireless communication technology so that the electronic devices provide the more diversified functions and are adapted to various daily requirements of the modern human beings.
The invention is directed to a method for peer to peer (P2P) signal synchronization, and P2P wireless communication device and system using the same. The P2P wireless communication devices may be synchronized with each other without the network architecture to be created in advance and without the use of the server. The invention has the advantage of saving the bandwidth and the advantage of the highly flexible system architecture.
According to a first aspect of the present invention, a method for P2P signal synchronization is provided. The method includes the following steps. A first P2P wireless communication device, having an effective range, is controlled to act as a master device. At least one second P2P wireless communication device, located in the effective range, is paired and connected with the first P2P wireless communication device. The first P2P wireless communication device broadcasts a synchronization signal when the first P2P wireless communication device acts as the master device. The at least one second P2P wireless communication device is switched to the master device and broadcasts the synchronization signal after the at least one second P2P wireless communication device receives the synchronization signal.
According to a second aspect of the present invention, a peer to peer (P2P) wireless communication device capable of performing P2P signal synchronization is provided. The device includes a P2P wireless communication unit and a control module. The P2P wireless communication unit performs P2P wireless communication with an external environment. The control module controls the P2P wireless communication unit and controls the P2P wireless communication device, having an effective range, to act as a master device. When at least one other P2P wireless communication device is located in the effective range, the P2P wireless communication device is paired and connected with the at least one other P2P wireless communication device. When the P2P wireless communication device acts as the master device, the control module controls the P2P wireless communication device to broadcast a synchronization signal. After the at least one other P2P wireless communication device receives the synchronization signal, the at least one other P2P wireless communication device is switched to the master device and broadcasts the synchronization signal.
According to a third aspect of the present invention, a peer to peer (P2P) wireless communication system capable of performing P2P signal synchronization is provided. The system includes a first P2P wireless communication device and at least one second P2P wireless communication device. The first P2P wireless communication device, having an effective range, acts as a master device. The at least one second P2P wireless communication device located in the effective range is paired and connected with the first P2P wireless communication device. When the first P2P wireless communication device acts as the master device, the first P2P wireless communication device further broadcasts a synchronization signal. After the at least one second P2P wireless communication device receives the synchronization signal, the at least one second P2P wireless communication device is switched to the master device and broadcasts the synchronization signal.
The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment(s). The following description is made with reference to the accompanying drawings.
After the at least one second P2P wireless communication device receives the synchronization signal, the at least one second P2P wireless communication device is synchronized with the first P2P wireless communication device. In addition, the at least one second P2P wireless communication device may further broadcast the synchronization signal so that the other P2P wireless communication device or devices may receive the synchronization signal, and the other P2P wireless communication device or devices may also be synchronized with the first P2P wireless communication device. Thus, multiple P2P wireless communication devices can be synchronized by controlling the P2P wireless communication device, which receives the synchronization signal, to be switched to the master device and to broadcast the synchronization signal. In addition, this embodiment can synchronize all the P2P wireless communication devices by only transmitting the synchronization signal without transmitting a lot of data. Furthermore, because no server has to be used, the architecture and the number of connected P2P wireless communication devices may be adjusted according to the condition, so that this embodiment further has the advantage of the high flexibility of the system architecture.
Illustrations will be made according to the P2P wireless communication device serving as a bluetooth device. However, this embodiment is also adapted to other types of P2P wireless communication devices.
The bluetooth device of this embodiment may be set as either the master device or a slave device.
Then, as shown in step 204, it is judged whether the number of slave devices, which are connected to the master device and in the active states, is greater than a predetermined number, such as the number specified by the bluetooth specification. If yes, the process enters step 206; or otherwise the process returns to the step 202. In the step 206, the searched mode of the bluetooth device is disabled and the bluetooth device is no longer connected to other slave devices.
Further details will be described according to one example.
First, the node 1 acts as the master device, the searched mode of the node 1 is enabled, and the node 1 has an effective range 402, as shown in
Thereafter, as shown in
As shown in
Thereafter, the nodes 2, 3 and 4 are switched to the master devices and the searched mode. For example, the node 1 may be continuously kept in the mode of the master device. However, this embodiment is not restricted thereto. At this time, as shown in
Next, the nodes 5 and 6 located within the effective range 404 are paired with the node 2, and the node 7 located within the effective range 406 is paired with the node 3. At this time, the nodes 2, 5 and 6 form a piconet, and the nodes 3 and 7 form another piconet. After pairing, the nodes 5, 6 and 7 are switched to the master device and the searched mode.
At this time, as shown in
When signal synchronization is to be performed on the bluetooth system constituted by the nodes 1 to 8, the flow chart of the operations of the bluetooth device is shown in
One example will be illustrated in the following.
Next, as shown in
Thereafter, as shown in
After the node 1 acting as the master device broadcasts the synchronization signal S, the states between the node 1, acting as the master device, and the nodes 2, 3 and 4, acting as the slave devices, are switched to disconnected states. Thereafter, the nodes 2, 3 and 4 are switched to the master devices, and broadcast the synchronization signal S, so that the other nodes in the piconet corresponding to the nodes 2, 3 and 4 can receive the synchronization signal S.
The advantage of switching to the disconnected states is that the states between the node 1 and the nodes 2, 3 and 4 need not to be continuously kept in the connected states so that the resource consumed by the connections may be saved. The connected state only has to be created again when the node 1 has the synchronization signal to be transmitted. In the disconnected state, the nodes 2, 3 and 4 can independently perform the operations to be carried out without being affected by the node 1. The same condition applies to other nodes.
If one node concurrently receives multiple synchronization signals, it is possible to judge which one serves as the main synchronization signal and to neglect the other synchronization signals according to some parameters contained in the synchronization signal. For example, it is possible to judge which synchronization signal is the later synchronization signal outputted by the node 1 among the concurrently received synchronization signals according to the time parameter contained in the synchronization signal, and only to perform the operation corresponding to the later synchronization signal.
When the bluetooth device 700 acts as the master device, the control module 704 controls the bluetooth device 700 to broadcast a synchronization signal. After the at least one other bluetooth device 706 receives the synchronization signal S, the at least one other bluetooth device 706 is switched to the master device and broadcasts the synchronization signal S.
The control module 704 may be achieved by a processor, firmware, or a processor in conjunction with the associated software.
In addition, in another embodiment, after the at least one second P2P wireless communication device receives the synchronization signal, the at least one second P2P wireless communication device may further transmit a receipt acknowledgement message to the first P2P wireless communication device. For example, when the node 2 of
Similarly, after the node 5 of
Preferably, the synchronization signal includes a command signal for making the at least one second P2P wireless communication device perform a predetermined operation, which corresponds to a to-be-performed operation requested by the first P2P wireless communication device. For example, the command signal, outputted from the node 1, can make the nodes 2 to 8 perform a predetermined operation, which corresponds to the to-be-performed operation requested by the node 1, so that the nodes 2 to 8 and the node 1 are synchronized in operation. For example, the command signal may also make pages of an electronic document, displayed on the nodes 2 to 8, be the same as the page of the electronic document, displayed on the node 1.
Also, if the nodes 1 to 8 read the same electronic document, then the node 1 can broadcast a command signal indicating going to a predetermined page, so that the nodes 2 to 8 automatically go to the predetermined page and the synchronization in operation can be achieved. If the invention is applied to the teaching, the node 1 is the bluetooth device used by the instructor and the nodes 2 to 8 are bluetooth devices used by the students, then the bluetooth devices of the nodes 2 to 8 can automatically go to the predetermined page when the instructor go to the predetermined page of the electronic document, so that the pages displayed on the bluetooth devices of the students are the same as that displayed on the bluetooth device of the instructor, and the teaching convenience can be significantly enhanced.
The comparison of this embodiment with the conventional computer classroom will be illustrated in the following. In some computer classrooms, teachers directly switch the frames, displayed on the computer screens of the students, to the frame displayed on the screen of the teacher through screen switching devices to facilitate the teaching. The conventional method has to transmit a lot of frame data to the computer screens of the students, and thus occupies a lot of network bandwidths and network resources. In addition, when the computer screens of the students are switched to the frame of the screen of the teacher, the students cannot operate their own computers. When this embodiment is applied to the teaching, only the synchronization signal has to be transmitted between the bluetooth device of the teacher and the bluetooth devices of the students to synchronize the bluetooth devices of the teacher and the student with each other in operation, and display the same page of the electronic document to achieve the desired teaching effect. The bandwidth used thereby is very low, so a lot of network resources may be saved. In addition, after the bluetooth devices of the students are synchronized with the bluetooth device of the teacher, the students still can operate their own bluetooth devices. For example, the student still can use his/her bluetooth device to highlight some key points, to write marks and the like. This embodiment is unlike the conventional method, which has the drawback that the student cannot operate his/her own computer after the frame of the computer screen of the student is switched to the frame of the screen of the teacher.
Furthermore, this embodiment may also be applied to the occasion when books are commonly read, such as the occasion of religious gathering, the moderator may ask the participants to go to a predetermined page for discussion. Using this embodiment can shorten the time for the participants to go to the predetermined page and provide the excellent convenience for the senior or operation retarded person.
The P2P wireless communication devices may be, for example, portable electronic devices, e-book readers, mobile phones, personal digital assistants, notebook computers, hand-held computers or electronic labels. Thus, the P2P wireless communication devices can form a P2P wireless communication system in various environments, so that the P2P wireless communication devices may be synchronized with each other. This embodiment does not need the network to be created in advance, and does not need the server or access point and has the extremely high convenience. In addition, the architecture of the P2P wireless communication system of this embodiment may be very flexible. That is, the number of, the positions of and the connections between the P2P wireless communication devices of the P2P wireless communication may be adjusted at any time. For example, even if the users go outdoors, the users still can use this embodiment to create the required P2P wireless communication system to complete the synchronization.
The synchronization signal may also be a command querying whether the P2P wireless communication device is present, and may be applied to the roll call mechanism of determining whether the members are present in the classroom, or the roll call operation of determining whether the members in a travel team leaded by a tourist guide are in attendance. Each P2P wireless communication device returns a receipt acknowledgement message, so that whether each P2P wireless communication device is in attendance can be judged, and the roll call operation can be finished immediately and conveniently. In addition, when the P2P wireless communication devices of this embodiment are electronic labels, the synchronization signal may be the signal for synchronously updating the contents of the electronic label.
Next, in step 804, a second bluetooth device, acting as a slave device and located within the effective range, receives the pair-link request and is paired with the first bluetooth device. If the pairing is not completed, the process enters step 806, in which the second bluetooth device and the first bluetooth device are not successfully paired. If the pairing is successfully finished, step 808 is performed.
In the step 808, the second bluetooth device and the first bluetooth device are successfully paired and connected with each other. Next, the first bluetooth device outputs a synchronization signal, and the second bluetooth device receives the synchronization signal. At this time, the second bluetooth device has been synchronized with the first bluetooth device. Thereafter, the state between the second bluetooth device and the first bluetooth device is switched to a disconnected state.
Then, in step 810, the second bluetooth device is switched to the master device, and broadcasts the pair-link request to other bluetooth device or devices. After the pairing succeeds, the second bluetooth device broadcasts the synchronization signal out. Thus, the requirement of synchronizing the bluetooth devices, which is the same as that of the first embodiment, may also be achieved. The other technological features and applications of the second embodiment are the same as those of the first embodiment, and detailed descriptions thereof will be omitted.
While the invention has been described by way of example and in terms of the preferred embodiment(s), it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 99135080 | Oct 2010 | TW | national |
