Abstract:
A communication system  100  allows for heterogeneous piconets/scattenets  100  where in multiple modes  110, 112  of transmission, one of Bluetooth  110  and one or more other modes of transmission  112  are possible. While at the same time maintaining synchronization between all the different modes of transmission  110, 112  in a given piconet and across a scatternet  100 . This allows for a communication device that can communicate using a plurality of transmission modes depending on the communication needs of the device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/228,850, entitled “Multi-mode, multi-media piconets/scatternets”, having attorney docket No. TI-3159PS, and filed on Aug. 29, 2000. 
     
    
     TECHNICAL FIELD  
       [0002]     This invention relates in general to the field of radio communications, and more specifically to a multi-mode radio frequency network.  
       BACKGROUND  
       [0003]     Previous communication systems allow for communication between different devices using a single mode of transmission. For example, a device communicating to other electronic devices over a Bluetooth piconet or scatternet (Bluetooth is a protocol for wireless communications over short distances developed by the Bluetooth Special Interest Group), or a portable computer communicating to a computer network using an Institute of Electrical and Electronic Engineers (IEEE) 802.11 (a or b) protocol, etc. Given the increased use of wireless communications in many everyday electronic devices (e.g., personal digital assistants (PDAs, portable computers, etc.) and the increased number of different communication protocols being used, a need exists in the art for a method and system which would allow a Bluetooth compliant device to be able to communicate using one or more other modes of communications, thereby allowing the device to communicate to some devices using the Bluetooth protocol, while communicating with other device(s) or the same device using another protocol, such as a higher speed IEEE 802.11 protocol or any one of a number of other communication protocols. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]     The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:  
         [0005]      FIG. 1  shows a diagram of a multi-mode radio communication network in accordance with the invention.  
         [0006]      FIG. 2  shows a time line of a master unit communicating to a first group of slave units using a first mode and to a second group of slave units using a second mode of communications.  
         [0007]      FIG. 3  shows a scatternet wherein a slave unit communicates to a master unit located in a first piconet using a first mode of transmission, and to a second master unit located in a second piconet using a second mode of transmission in accordance with the invention.  
         [0008]      FIG. 4  shows a scatternet wherein a device acts as a master in one piconet and as a slave unit in a second piconet in accordance with the invention.  
         [0009]      FIG. 5  is a diagram highlighting timing synchronization between two modes in accordance with the invention.  
         [0010]      FIG. 6  shows how synchronization between two modes is maintained at the physical layer in accordance with the invention.  
         [0011]      FIG. 7  shows a timing diagram highlighting “within mode” synchronization in accordance with the invention.  
         [0012]      FIG. 8  shows a timing diagram highlighting “across mode” synchronization in accordance with the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figure.  
         [0014]     The present invention provides for a heterogeneous radio network where a master unit communicates using voice or data to a first group of slave units in a first mode of operation, such as a Bluetooth mode, and communicates to a second group of slave units in a second mode, such as an IEEE 802.11 (a or b) protocol, etc. The master unit maintains synchronization with the slave units in the first mode and periodically communicates with them while at the same time servicing slave units using the second mode of operation. The second communication protocol beside the Bluetooth protocol that can be used by the device in accordance with the invention can include for example the IEEE 802.11 protocol as mentioned previously, High Rate Bluetooth protocol, the Global System of Mobile Communications (GSM) protocol, General Packet Radio Service (GPRS), Wideband Code Division Multiple Access (W-CDMA) protocol, other wireless local area network communication protocols, etc., but is not limited to these protocols. The present invention teaches a technique whereby a device can synchronize its communications using the Bluetooth protocol and one or more other protocols in order to increase the usefulness of the device in question.  
         [0015]     In  FIG. 1  there is shown a system diagram of a radio network  100  in accordance with the invention. Radio network  100  includes a master unit  102  that communicates with two slave units  104 ,  108  using a first mode of communications (Mode 1), such as via a Bluetooth piconet  110 , and is also able to communicate with a slave unit  106  using a second mode of operation (Mode 2) such as using an 802.11 protocol. Likewise in accordance with the invention, slave units can simultaneously exchange voice/data in a scatternet wherein one or more piconets in the scatternet are Bluetooth piconets (mode 1) and one or more piconets use a different mode of communication (mode 2) with master  102 . In  FIG. 2 , a time line showing an illustrative example of time slots in which the master unit  102  communicates in mode 1 (Bluetooth mode) during time slots  201 , and in the IEEE 802.11 mode 2 during time slots  206  (or using any one of a number of other communication protocols) is shown. The mode 1 time slots  201  are further broken down into time periods  202  and  204 . In time period  202 , the Master  102  communicates with other Bluetooth devices such as slave units  104 ,  108  using Bluetooth paging, sniff, beacon, etc. modes. In time period  204 , the master unit  102  selects a good 22 MHz band using the Bluetooth probe, listen and select functions. In time period  206 , the master unit  102  communicates with salve unit  106  using the second mode of communication, for example, 802.11.  
         [0016]     In accordance with the invention, slave units can be simultaneously exchanging voice or data in a scatternet wherein one piconet is a Bluetooth piconet (mode 1) and the other piconet is a higher speed mode of operation (mode 2). Referring to  FIG. 3 , there is shown a scatternet  300  comprising two piconets  302  and  304 . In this scenario, a slave unit  306  communicates to a first master unit  308  in bluetooth mode (Mode 1) that is in the first piconet  302 , and also communicates with a second master unit  310  that is operating in a second piconet  304 . Other combination of the above scenario where a slave unit communicates to multiple piconets that are themselves multi-mode piconets are also possible.  
         [0017]     In still a further embodiment, in  FIG. 4  there is shown a master unit  406  that can be communicating to one or more slave units  406 ,  408  in a first piconet  402  using Bluetooth and another communication protocol (Mode 2), and at the same time function as a slave unit in a second piconet  404 . In this scenario, device  406  acts as a Master in one piconet  402 , and a slave unit in a second piconet  404 , while communicating using multiple modes.  
         [0018]     As has been shown above, the present invention provides for a device that can communicate not only using Bluetooth but also using one or more other modes of communications. As shown above, this multi-mode capability can be used across piconets and scatternets. Synchronization between all the different modes of transmission is maintained in a given piconet and across a scatternet comprising multiple piconets.  
         [0019]     The synchronization between the different modes within a device is maintained as shown in  FIG. 5 . With the timing information in the device being shared in the multiple modes of communication. The timing information synchronization is maintained explicitly at the physical (PHY) layer to allow rapid mode switching within the piconet as shown in  FIG. 6 .  
         [0020]     Regarding synchronization, synchronization packets in mode 2 (non-Bluetooth mode) can be “within mode synchronous”, i.e., synchronous only in mode 2, and they stop when the master enters mode 1. Within mode synchronous is shown in  FIG. 7 , with synchronous packets occurring at time periods  702  and  706  while in mode 2, and no packets occurring in time period  704  while in the Bluetooth mode (mode 1).  
         [0021]     Synchronization packets in mode 2 can also be “across modes synchronous” when the time between packets is larger than the time the master spends in mode 1 (Bluetooth mode). The same can be applied for synchronous packets in mode 1. In  FIG. 8 , there is shown a time line highlighting “within mode synchronous packets”. Synchronous packets occur in time periods  802  and  804 .  
         [0022]     While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.