Patent Publication Number: US-7711373-B2

Title: Multiradio control interface

Description:
RELATED CASES 
   This Application is related to application Ser. No. 11/431,706, filed May 11, 2006, entitled “MULTIRADIO CONTROL INTERFACE ELEMENT IN MODEM” and application Ser. No. 11/431,542, filed May 11, 2006, entitled “DISTRIBUTED MULTIRADIO CONTROLLER”, both of which are assigned to Nokia Corporation. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a system for managing multiple radio modems imbedded in a wireless communication device, and more specifically to a multiradio control system for scheduling a plurality of active radio modems so as to avoid communication conflicts. 
   DESCRIPTION OF PRIOR ART 
   Modern society has quickly adopted, and become reliant upon, handheld devices for wireless communication. For example, cellular telephones continue to proliferate in the global marketplace due to technological improvements in both the quality of the communication and the functionality of the devices. These wireless communication devices (WCDs) have become commonplace for both personal and business use, allowing users to transmit and receive voice, text and graphical data from a multitude of geographic locations. The communication networks utilized by these devices span different frequencies and cover different transmission distances, each having strengths desirable for various applications. 
   Cellular networks facilitate WCD communication over large geographic areas. These network technologies have commonly been divided by generations, starting in the late 1970s to early 1980s with first generation (1G) analog cellular telephones that provided baseline voice communications, to modern digital cellular telephones. GSM is an example of a widely employed 2G digital cellular network communicating in the 900 MHZ/1.8 GHZ bands in Europe and at 850 MHz and 1.9 GHZ in the United States. This network provides voice communication and also supports the transmission of textual data via the Short Messaging Service (SMS). SMS allows a WCD to transmit and receive text messages of up to 160 characters, while providing data transfer to packet networks, ISDN and POTS users at 9.6 Kbps. The Multimedia Messaging Service (MMS), an enhanced messaging system allowing for the transmission of sound, graphics and video files in addition to simple text, has also become available in certain devices. Soon emerging technologies such as Digital Video Broadcasting for Handheld Devices (DVB-H) will make streaming digital video, and other similar content, available via direct transmission to a WCD. While long-range communication networks like GSM are a well-accepted means for transmitting and receiving data, due to cost, traffic and legislative concerns, these networks may not be appropriate for all data applications. 
   Short-range wireless networks provide communication solutions that avoid some of the problems seen in large cellular networks. Bluetooth™ is an example of a short-range wireless technology quickly gaining acceptance in the marketplace. A Bluetooth™ enabled WCD transmits and receives data at a rate of 720 Kbps within a range of 10 meters, and may transmit up to 100 meters with additional power boosting. A user does not actively instigate a Bluetooth network. Instead, a plurality of devices within operating range of each other will automatically form a network group called a “piconet”. Any device may promote itself to the master of the piconet, allowing it to control data exchanges with up to seven “active” slaves and 255 “parked” slaves. Active slaves exchange data based on the clock timing of the master. Parked slaves monitor a beacon signal in order to stay synchronized with the master, and wait for an active slot to become available. These devices continually switch between various active communication and power saving modes in order to transmit data to other piconet members. In addition to Bluetooth™ other popular short-range wireless networks include WLAN (of which “Wi-Fi” local access points communicating in accordance with the IEEE 802.11 standard, is an example), WUSB, UWB, ZigBee (802.15.4, 802.15.4a), and UHF RFID. All of these wireless mediums have features and advantages that make them appropriate for various applications. 
   More recently, manufacturers have also begun to incorporate various resources for providing enhanced functionality in WCDs (e.g., components and software for performing close-proximity wireless information exchanges). Sensors and/or scanners may be used to read visual or electronic information into a device. A transaction may involve a user holding their WCD in proximity to a target, aiming their WCD at an object (e.g., to take a picture) or sweeping the device over a printed tag or document. Machine-readable technologies such as radio frequency identification (RFID), Infra-red (IR) communication, optical character recognition (OCR) and various other types of visual, electronic and magnetic scanning are used to quickly input desired information into the WCD without the need for manual entry by a user. 
   Device manufacturers are continuing to incorporate as many of the previously indicated exemplary communication features as possible into wireless communication devices in an attempt to bring powerful, “do-all” devices to market. Devices incorporating long-range, short-range and machine readable communication resources also often include multiple mediums for each category. This allows a communication device to flexibly adjust to its surroundings, for example, communicating both with a WLAN access point and a Bluetooth™ communication accessory, possibly at the same time. 
   Given the large array communications options compiled into one device, it is foreseeable that a user will want to employ a WCD to its full potential when replacing other productivity related devices. For example, a user may use a high powered WCD to replace other traditional, more cumbersome phones, computers, etc. In these situations, a WCD may be communicating simultaneously over numerous different wireless mediums. A user may use multiple peripheral Bluetooth™ devices (e.g., a headset and a keyboard) while having a voice conversation over GSM and interacting with a WLAN access point in order to access an Internet website. Problems may occur when these simultaneous communications cause interference with each other. Even if a communication medium does not have an identical operating frequency as another medium, a radio modem may cause extraneous interference to another medium. Further, it is also possible for the combined effects of two or more simultaneously operating radios to create intermodulation effects to another bandwidth due to harmonic effects. These disturbances may cause errors resulting in the required retransmission of lost packets, and the overall degradation of performance for one or more communication mediums. 
   The utility of a communication device equipped with the ability to communicate over multiple wireless communication mediums is greatly hindered if these communications can only be employed one at a time. Therefore, what is needed is a system to manage these various communication mediums so that they can function simultaneously with a negligible impact in performance. The system should be able to identify and understand the functionality of each wireless medium, and should be able to quickly react on changing conditions in the environment and control each medium so that interference is minimized. 
   SUMMARY OF INVENTION 
   The present invention includes a terminal, method, computer program, system and chipset for managing the simultaneous operation of a plurality of radio modems embedded in the same wireless communication device. The operations of these radio modems may be directly controlled by a multiradio control system also integrated into the same wireless device. 
   The multiradio control system (MCS) may include at least one multiradio controller (MRC). The MRC may communicate with each radio modem through either a communication interface common to the general control system of the WCD (common interface), or alternatively, it may utilize a specialized interface dedicated to transactions of the multiradio control system (MCS interface). While the common interface may be used to convey information between the MRC and the radio modems, it may suffer from communication delays due to ordinary traffic in the master control system (e.g., traffic from multiple running applications, user interactions, etc.). However, the MCS interfaces directly couple the MRC and communication resources of the WCD, and may allow the quick transmission of delay sensitive operational information and control commands regardless of master control system traffic. Delay sensitive information may be requested by the MRC, or may be provided by one or more of the plurality of radio modems if a change occurs during operation. 
   The MRC may use both delay tolerant information received from the common interface system, and delay sensitive information received, in some cases, from the dedicated MCS interface system to control overall communications for the WCD. The MRC monitors active wireless communications to determine if a potential conflict exists. In order to avoid a conflict, the MRC may schedule modems by directly enabling or disabling them for time periods through commands issued to these radio modems. While any or all of these commands may be sent through the common interface system, the MCS interface system, which is dedicated only to conveying delay-sensitive information, may provide a direct route between the MRC and the radio modems that is immune from any communication overhead caused by other transactions in the master control system. 

   
     DESCRIPTION OF DRAWINGS 
     The invention will be further understood from the following detailed description of a preferred embodiment, taken in conjunction with appended drawings, in which: 
       FIG. 1  discloses an exemplary wireless operational environment, including wireless communication mediums of different effective range. 
       FIG. 2  discloses a modular description of an exemplary wireless communication device usable with at least one embodiment of the present invention. 
       FIG. 3  discloses an exemplary structural description of the wireless communication device previously described in  FIG. 2 . 
       FIG. 4  discloses an exemplary operational description of a wireless communication device utilizing a wireless communication medium in accordance with at least one embodiment of the present invention. 
       FIG. 5  discloses an operational example wherein interference occurs when utilizing multiple radio modems simultaneously within the same wireless communication device. 
       FIG. 6A  discloses an exemplary structural description of a wireless communication device including a multiradio controller in accordance with at least one embodiment of the present invention. 
       FIG. 6B  discloses a more detailed structural diagram of  FIG. 6A  including the multiradio controller and the radio modems. 
       FIG. 6C  discloses an exemplary operational description of a wireless communication device including a multiradio controller in accordance with at least one embodiment of the present invention. 
       FIG. 7A  discloses an exemplary structural description of a wireless communication device including a multiradio control system in accordance with at least one embodiment of the present invention. 
       FIG. 7B  discloses a more detailed structural diagram of  FIG. 7A  including the multiradio control system and the radio modems. 
       FIG. 7C  discloses an exemplary operational description of a wireless communication device including a multiradio control system in accordance with at least one embodiment of the present invention. 
       FIG. 8  discloses a more specific example of the functionality described in  FIG. 7A-7C . 
       FIG. 9  discloses an exemplary information packet usable with at least one embodiment of the present invention. 
       FIG. 10  discloses exemplary timing diagrams for wireless radio modems usable with the present invention. 
       FIG. 11  discloses a flowchart explaining an exemplary process by which a multiradio controller receives information from a plurality of radio modems in accordance with at least one embodiment of the present invention. 
       FIG. 12  discloses a flowchart explaining an exemplary process by which a multiradio controller manages a plurality of radio modems when a potential conflict exists in accordance with at least one embodiment of the present invention. 
       FIG. 13A  discloses an exemplary process by which information is sent from a radio modem to the multiradio controller in accordance with at least one embodiment of the present invention. 
       FIG. 13B  discloses an exemplary process by which information is sent from another radio modem to the multiradio controller in accordance with at least one embodiment of the present invention. 
       FIG. 14  discloses a flowchart explaining an exemplary communication process in accordance with at least one embodiment of the present invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENT 
   While the invention has been described in preferred embodiments, various changes can be made therein without departing from the spirit and scope of the invention, as described in the appended claims. 
   I. Wireless Communication Over Different Communication Networks. 
   A WCD may both transmit and receive information over a wide array of wireless communication networks, each with different advantages regarding speed, range, quality (error correction), security (encoding), etc. These characteristics will dictate the amount of information that may be transferred to a receiving device, and the duration of the information transfer.  FIG. 1  includes a diagram of a WCD and how it interacts with various types of wireless networks. 
   In the example pictured in  FIG. 1 , user  110  possesses WCD  100 . This device may be anything from a basic cellular handset to a more complex device such as a wirelessly enabled palmtop or laptop computer. Near Field Communications (NFC)  130  include various transponder-type interactions wherein normally only the scanning device requires its own power source. WCD  100  scans source  120  via short-range communications. A transponder in source  120  may use the energy and/or clock signal contained within the scanning signal, as in the case of RFID communication, to respond with data stored in the transponder. These types of technologies usually have an effective transmission range on the order of ten feet, and may be able to deliver stored data in amounts from 96 bits to over a megabit (or 125 Kbytes) relatively quickly. These features make such technologies well suited for identification purposes, such as to receive an account number for a public transportation provider, a key code for an automatic electronic door lock, an account number for a credit or debit transaction, etc. 
   The transmission range between two devices may be extended if both devices are capable of performing powered communications. Short-range active communications  140  includes applications wherein the sending and receiving devices are both active. An exemplary situation would include user  1   10  coming within effective transmission range of a Bluetooth™, WLAN, UWB, WUSB, etc. access point. The amount of information to be conveyed is unlimited, except that it must all be transferred in the time when user  110  is within effective transmission range of the access point. This duration is extremely limited if the user is, for example, strolling through a shopping mall or walking down a street. Due to the higher complexity of these wireless networks, additional time is also required to establish the initial connection to WCD  100 , which may be increased if there are many devices queued for service in the area proximate to the access point. The effective transmission range of these networks depends on the technology, and may be from 32 ft. to over 300 ft. 
   Long-range networks  150  are used to provide virtually uninterrupted communication coverage for WCD  100 . Land-based radio stations or satellites are used to relay various communications transactions worldwide. While these systems are extremely functional, the use of these systems are often charged on a per-minute basis to user  110 , not including additional charges for data transfer (e.g., wireless Internet access). Further, the regulations covering these systems cause additional overhead for both the users and providers, making the use of these systems more cumbersome. 
   In view of the above, it becomes easy to understand the need for a variety of different communication resources combined into a single WCD. Since these types of devices are being used as replacements for a variety of conventional communications means, including land-land telephones, low-functionality cellular handsets, laptops enabled with wireless communications, etc., the devices must be able to easily adapt to a variety of different applications (e.g., voice communications, business programs, GPS, Internet communications, etc.) in a variety of different environments (e.g. office, automobile, outdoors, arenas, shops, etc.) 
   II. Wireless Communication Device 
   As previously described, the present invention may be implemented using a variety of wireless communication equipment. Therefore, it is important to understand the communication tools available to user  100  before exploring the present invention. For example, in the case of a cellular telephone or other handheld wireless devices, the integrated data handling capabilities of the device play an important role in facilitating transactions between the transmitting and receiving devices. 
     FIG. 2  discloses an exemplary modular layout for a wireless communication device usable with the present invention. WCD  100  is broken down into modules representing the functional aspects of the device. These functions may be performed by the various combinations of software and/or hardware components discussed below. 
   Control module  210  regulates the operation of the device. Inputs may be received from various other modules included within WCD  100 . For example, interference sensing module  220  may use various techniques known in the art to sense sources of environmental interference within the effective transmission range of the wireless communication device. Control module  210  interprets these data inputs, and in response, may issue control commands to the other modules in WCD  100 . 
   Communications module  230  incorporates all of the communications aspects of WCD  100 . As shown in  FIG. 2 , communications module  230  may include, for example, long-range communications module  232 , short-range communications module  234  and machine-readable data module  236  (e.g., for NFC). Communications module  230  utilizes at least these sub-modules to receive a multitude of different types of communication from both local and long distance sources, and to transmit data to recipient devices within the transmission range of WCD  100 . Communications module  230  may be triggered by control module  210 , or by control resources local to the module responding to sensed messages, environmental influences and/or other devices in proximity to WCD  100 . 
   User interface module  240  includes visual, audible and tactile elements which allow the user  110  to receive data from, and enter data into, the device. The data entered by user  110  may be interpreted by control module  210  to affect the behavior of WCD  100 . User-inputted data may also be transmitted by communications module  230  to other devices within effective transmission range. Other devices in transmission range may also send information to WCD  100  via communications module  230 , and control module  210  may cause this information to be transferred to user interface module  240  for presentment to the user. 
   Applications module  250  incorporates all other hardware and/or software applications on WCD  100 . These applications may include sensors, interfaces, utilities, interpreters, data applications, etc., and may be invoked by control module  210  to read information provided by the various modules and in turn supply information to requesting modules in WCD  100 . 
     FIG. 3  discloses an exemplary structural layout of WCD  100  according to an embodiment of the present invention that may be used to implement the functionality of the modular system previously described in  FIG. 2 . Processor  300  controls overall device operation. As shown in  FIG. 3 , processor  300  is coupled to communications sections  310 ,  312 ,  320  and  340 . Processor  300  may be implemented with one or more microprocessors that are each capable of executing software instructions stored in memory  330 . 
   Memory  330  may include random access memory (RAM), read only memory (ROM), and/or flash memory, and stores information in the form of data and software components (also referred to herein as modules). The data stored by memory  330  may be associated with particular software components. In addition, this data may be associated with databases, such as a bookmark database or a business database for scheduling, email, etc. 
   The software components stored by memory  330  include instructions that can be executed by processor  300 . Various types of software components may be stored in memory  330 . For instance, memory  330  may store software components that control the operation of communication sections  310 ,  312 ,  320  and  340 . Memory  330  may also store software components including a firewall, a service guide manager, a bookmark database, user interface manager, and any communications utilities modules required to support WCD  100 . 
   Long-range communications  310  performs functions related to the exchange of information over large geographic areas (such as cellular networks) via an antenna. These communication methods include technologies from the previously described 1G to 3G. In addition to basic voice communications (e.g., via GSM), long-range communications  310  may operate to establish data communications sessions, such as General Packet Radio Service (GPRS) sessions and/or Universal Mobile Telecommunications System (UMTS) sessions. Also, long-range communications  310  may operate to transmit and receive messages, such as short messaging service (SMS) messages and/or multimedia messaging service (MMS) messages. As disclosed in  FIG. 3 , Long-range communications  310  may be composed of one or more subsystems supporting various long-range communications mediums. These subsystems may, for example, be radio modems enabled for various types of long-range wireless communication. 
   As a subset of long-range communications  310 , or alternatively operating as an independent module separately connected to processor  300 , broadcast receivers  312  allows WCD  100  to receive transmission messages via mediums such as Analog Radio, Digital Video Broadcast for Handheld Devices (DVB-H), Digital Audio Broadcasting (DAB), etc. These transmissions may be encoded so that only certain designated receiving devices may access the transmission content, and may contain text, audio or video information. In at least one example, WCD  100  may receive these transmissions and use information contained within the transmission signal to determine if the device is permitted to view the received content. As in the case of long-range communications  310 , broadcast receivers  312  may be comprised of one or more radio modems utilized to receive a variety of broadcast information. 
   Short-range communications  320  is responsible for functions involving the exchange of information across short-range wireless networks. As described above and depicted in  FIG. 3 , examples of such short-range communications  320  are not limited to Bluetooth™, WLAN, UWB, Zigbee, UHF RFID, and Wireless USB connections. Accordingly, short-range communications  320  performs functions related to the establishment of short-range connections, as well as processing related to the transmission and reception of information via such connections. Short-range communications  320  may be composed of one or more subsystem made up of, for example, various radio modems employed to communicate via the previously indicated assortment of short range wireless mediums. 
   Short-range input device  340 , also depicted in  FIG. 3 , may provide functionality related to the short-range scanning of machine-readable data (e.g., for NFC). For example, processor  300  may control short-range input device  340  to generate RF signals for activating an RFID transponder, and may in turn control the reception of signals from an RFID transponder. Other short-range scanning methods for reading machine-readable data that may be supported by the short-range input device  340  are not limited to IR communications, linear and  2 -D (e.g., QR) bar code readers (including processes related to interpreting UPC labels), and optical character recognition devices for reading magnetic, UV, conductive or other types of coded data that may be provided in a tag using suitable ink. In order for the short-range input device  340  to scan the aforementioned types of machine-readable data, the input device may include a multitude of optical detectors, magnetic detectors, CCDs or other sensors known in the art for interpreting machine-readable information. 
   As further shown in  FIG. 3 , user interface  350  is also coupled to processor  300 . User interface  350  facilitates the exchange of information with a user.  FIG. 3  shows that user interface  350  includes a user input  360  and a user output  370 . User input  360  may include one or more components that allow a user to input information. Examples of such components include keypads, touch screens, and microphones. User output  370  allows a user to receive information from the device. Thus, user output portion  370  may include various components, such as a display, light emitting diodes (LED), tactile emitters and one or more audio speakers. Exemplary displays include liquid crystal displays (LCDs), and other video displays. 
   WCD  100  may also include one or more transponders  380 . This is essentially a passive device which may be programmed by processor  300  with information to be delivered in response to a scan from an outside source. For example, an RFID scanner mounted in a entryway may continuously emit radio frequency waves. When a person with a device containing transponder  380  walks through the door, the transponder is energized and may respond with information identifying the device, the person, etc. 
   Hardware corresponding to communications sections  310 ,  312 ,  320  and  340  provide for the transmission and reception of signals. Accordingly, these portions may include components (e.g., electronics) that perform functions, such as modulation, demodulation, amplification, and filtering. These portions may be locally controlled, or controlled by processor  300  in accordance with software communications components stored in memory  330 . 
   The elements shown in  FIG. 3  may be constituted and coupled according to various techniques in order to produce the functionality described in  FIG. 2 . One such technique involves coupling separate hardware components corresponding to processor  300 , communications sections  310 ,  312  and  320 , memory  330 , short-range input device  340 , user interface  350 , transponder  380 , etc. through one or more bus interfaces. Alternatively, any and/or all of the individual components may be replaced by an integrated circuit in the form of a programmable logic device, gate array, ASIC, multi-chip module, etc. programmed to replicate the functions of the stand-alone devices. In addition, each of these components is coupled to a power source, such as a removable and/or rechargeable battery (not shown). 
   The user interface  350  may interact with a communications utilities software component, also contained in memory  330 , which provides for the establishment of service sessions using long-range communications  310  and/or short-range communications  320 . The communications utilities component may include various routines that allow the reception of services from remote devices according to mediums such as the Wireless Application Medium (WAP), Hypertext Markup Language (HTML) variants like Compact HTML (CHTML), etc. 
   III. Exemplary Operation of a Wireless Communication Device Including Potential Interference Problems Encountered. 
     FIG. 4  discloses a stack approach to understanding the operation of a WCD. At the top level  400 , user  110  interacts with WCD  100 . The interaction involves user  110  entering information via user input  360  and receiving information from user output  370  in order to activate functionality in application level  410 . In the application level, programs related to specific functionality within the device interact with both the user and the system level. These programs include applications for visual information (e.g., web browser, DVB-H receiver, etc.), audio information (e.g., cellular telephone, voice mail, conferencing software, DAB or analog radio receiver, etc.), recording information (e.g., digital photography software, word processing, scheduling, etc.) or other information processing. Actions initiated at application level  410  may require information to be sent from or received into WCD  100 . In the example of  FIG. 4 , data is requested to be sent to a recipient device via Bluetooth™ communication. As a result, application level  410  may then call resources in the system level to initiate the required processing and routing of data. 
   System level  420  processes data requests and routes the data for transmission. Processing may include, for example, calculation, translation, conversion and/or packetizing the data. The information may then be routed to an appropriate communication resource in the service level. If the desired communication resource is active and available in the service level  430 , the packets may be routed to a radio modem for delivery via wireless transmission. There may be a plurality of modems operating using different wireless mediums. For example, in  FIG. 4 , modem  4  is activated and able to send packets using Bluetooth™ communication. However, a radio modem (as a hardware resource) need not be dedicated only to a specific wireless medium, and may be used for different types of communication depending on the requirements of the wireless medium and the hardware characteristics of the radio modem. 
     FIG. 5  discloses a situation wherein the above described exemplary operational process may cause more than one radio modem to become active. In this case, WCD  100  is both transmitting and receiving information via wireless communication over a multitude of mediums. WCD  100  may be interacting with various secondary devices such as those grouped at  500 . For example, these devices may include cellular handsets communicating via long-range wireless communication like GSM, wireless headsets communicating via Bluetooth™, Internet access points communicating via WLAN, etc. 
   Problems may occur when some or all of these communications are carried on simultaneously. As further shown in  FIG. 5 , multiple modems operating simultaneously may cause interference for each other. Such a situation may be encountered when WCD  100  is communicating with more than one external device (as previously described). In an exemplary extreme case, devices with modems simultaneously communicating via Bluetooth™, WLAN and wireless USB would encounter substantial overlap since all of these wireless mediums operate in the 2.4 GHz band. The interference, shown as an overlapping portion of the fields depicted in  FIG. 5 , would cause packets to be lost and the need for retransmission of these lost packets. Retransmission requires that future time slots be used to retransmit lost information, and therefore, overall communications performance will at least be reduced, if the signal is not lost completely. The present invention, in at least one embodiment, seeks to manage such situations where communications are occurring simultaneously so that anticipated interference is minimized or totally avoided, and as a result, both speed and quality are maximized. 
   IV. A Wireless Communication Device Including a Multiradio Controller. 
   In an attempt to better manage communications in WCD  100 , an additional controller dedicated to managing wireless communications may be introduced. WCD  100 , as pictured in  FIG. 6A , includes a multiradio controller (MRC)  600 . MRC  600  is coupled to the master control system of WCD  100 . This coupling enables MRC  600  to communicate with radio modems or other similar devices in communications modules  310   312 ,  320  and  340  via the master operating system of WCD  100 . While this configuration may in some cases improve overall wireless communications efficiency for WCD  100 , problems may occur when WCD  100  becomes busy (e.g., when the control system of WCD  100  is employed in multitasking many different simultaneous operations, both communications and non-communications related). 
     FIG. 6B  discloses in detail at least one embodiment of WCD  100 , which may include multiradio controller (MRC)  600  introduced in  FIG. 6A . MRC  600  includes common interface  620  by which information may be sent or received through master control system  640 . Further, each radio modem  610  or similar communication device  630 , for example an RFID scanner for scanning machine-readable information, may also include some sort of common interface  620  for communicating with master control system  640 . As a result, all information, commands, etc. occurring between radio modems  610 , similar devices  630  and MRC  600  are conveyed by the communications resources of master control system  640 . The possible effect of sharing communications resources with all the other functional modules within WCD  100  will be discussed with respect to  FIG. 6C . 
     FIG. 6C  discloses an operational diagram similar to  FIG. 4  including the effect of MRC  600 . In this system MRC  600  may receive operational data from the master operating system of WCD  100 , concerning for example applications running in application level  410 , and status data from the various radio communication devices in service level  430 . MRC  600  may use this information to issue scheduling commands to the communication devices in service level  430  in an attempt to avoid communication problems. However, problems may occur when the operations of WCD  100  are fully employed. Since the various applications in application level  410 , the operating system in system level  420 , the communications devices in service level  430  and MRC  600  must all share the same communications system, delays may occur when all aspects of WCD  100  are trying to communicate on the common interface system  620 . As a result, delay sensitive information regarding both communication resource status information and radio modem  610  control information may become delayed, nullifying any beneficial effect from MRC  600 . Therefore, a system better able to handle the differentiation and routing of delay sensitive information is required if the beneficial effect of MRC  600  is to be realized. 
   V. A Wireless Communication Device Including a Multiradio Control System. 
     FIG. 7A  introduces MRC  600  as part of a multiradio control system (MCS)  700  in WCD  100 . MCS  700  directly links the communications resources of modules  310 , 312 , 320  and  340  to MRC  600 . MCS  700  may provide a dedicated low-traffic communication structure for carrying delay sensitive information both to and from MRC  600 . 
   Additional detail is shown in  FIG. 7B . MCS  700  forms a direct link between MRC  600  and the communication resources of WCD  100 . This link may be established by a system of dedicated MCS interfaces  710  and  720 . For example, MCS interface  720  may be coupled to MRC  600 . MCS Interfaces  710  may connect radio modems  610  and other similar communications devices  630  to MCS  700  in order to form an information conveyance for allowing delay sensitive information to travel to and from MRC  600 . In this way, the abilities of MRC  600  are no longer influenced by the processing load of master control system  640 . As a result, any information still communicated by master control system  640  to and from MRC  600  may be deemed delay tolerant, and therefore, the actual arrival time of this information does not substantially influence system performance. On the other hand, all delay sensitive information is directed to MCS  700 , and therefore is insulated from the loading of the master control system. 
   The effect of MCS  700  is seen in  FIG. 7C . Information may now be received in MRC  600  from at least two sources. System level  420  may continue to provide information to MRC  600  through master control system  640 . In addition, service level  430  may specifically provide delay sensitive information conveyed by MCS  700 . MRC  600  may distinguish between these two classes of information and act accordingly. Delay tolerant information may include information that typically does not change when a radio modem is actively engaged in communication, such as radio mode information (e.g., GPRS, Bluetooth™, WLAN, etc.), priority information that may be defined by user settings, the specific service the radio is driving (QoS, real time/non real time), etc. Since delay tolerant information changes infrequently, it may be delivered in due course by master control system  640  of WCD  100 . Alternatively, delay sensitive (or time sensitive) information includes at least modem operational information that frequently changes during the course of a wireless connection, and therefore, requires immediate update. As a result, delay sensitive information may need to be delivered directly from the plurality of radio modems  610  through the MCS interfaces  710  and  720  to MRC  600 , and may include radio modem synchronization information. Delay sensitive information may be provided in response to a request by MRC  600 , or may be delivered as a result of a change in radio modem settings during transmission, such as due to wireless handover or handoff. 
     FIG. 8  discloses a more specific example of the interaction between MRC  600 , MCS  700  and a radio modem  610 . MRC  600  requires a bi-directional multipoint control interface for each radio under control. In this example, MCS  700  may be used to (1) Get synchronization information from the radio modem  610  to MRC  600 , and (2) Provide radio activity control signals from MRC  600  to the radio modem  610  (enable/disable transmission and/or reception). In addition, as previously stated, MCS  700  may be used to communicate radio parameters that are delay sensitive from a controlling point of view between MRC  600  and the radio modem  610 . One example of parameters that may be communicated over MCS  700  is the packet type based priority information from MRC  600  to radio modem  610 . The packet type based priority information can be used, for example, to allow a WLAN modem to transmit acknowledgement type packets even though the radio activity control signal is not allowing the transmission. This packet type based priority information is typically communicated less frequently than the radio activity control signals. MCS interface  710  can be shared between different radio modems (multipoint) but it cannot be shared with any other functionality that could limit the usage of MCS interface  710  from latency point of view. 
   MCS  700  is used primarily to communicate the enabled/disabled radio activity periods from MRC  600  to the radio modem  610  and in turn get synchronization indications from the radio modems back to MRC  600 . The control signals from MRC  600  that enable/disable a radio modem  610  should be built on a modem&#39;s periodic events. MRC  600  gets this information about a radio modem&#39;s periodic events from synchronization indications issued by the radio modem  610 . This kind of event can be, for example, frame clock event in GSM (4.615 ms), slot clock event in BT (625 us) or any multiple of these. A radio modem  610  may send its synchronization indications when (1) MRC requests it, (2) a radio modem internal time reference is changed (e.g. due to handover or handoff). The latency requirement for the synchronization signal is not critical as long as the delay is constant within a few microseconds. The fixed delays can be taken into account in MRC  600  scheduling logic. 
   The radio modem activity control is based on the knowledge of when the active radio modems  610  are about to transmit (or receive) in the specific connection mode in which the radio modems  610  are currently operating. The connection mode of a radio modem  610  is mapped to the time domain operation in MRC  600 . As an example, for a GSM speech connection, MRC  600  has knowledge about all traffic patterns of GSM. This means that MRC  600  recognizes that the speech connection in GSM includes one transmission slot of length 577 μs, followed by an empty slot after which is the reception slot of 577 μs, two empty slots, monitoring (RX on), two empty slots, and then it repeats. Dual transfer mode means two transmission slots, empty slot, reception slot, empty slot, monitoring and two empty slots. When all traffic patterns that are known a priori by the MRC  600 , it only needs to know when the transmission slot occurs in time to gain knowledge of when GSM radio is active. This information may be obtained with the radio synchronization signal. When the active radio modem  610  is about to transmit (or receive) it must check every time whether the modem activity control signal from MRC  600  permits the communication. MRC  600  is always either allowing or disabling the transmission of one full radio transmission block (e.g. GSM slot). 
   An example message packet  900  is disclosed in  FIG. 9 . Example message packet  900  includes activity pattern information that may be provided by MRC  600  to radio modems  610 . The data payload of packet  900  may include at least Message ID information, allowed/disallowed transmission (Tx) period information, allowed/disallowed reception (Rx) period information, Tx/Rx periodicity (how often the Tx/Rx activities contained in the period information occur), and validity information describing when the activity pattern becomes valid and whether the new activity pattern is replacing or added to the existing one. The data payload of packet  900 , as shown, may consist of multiple allowed/disallowed periods for transmission or reception (e.g., Tx period  1 ,  2  . . . ) each containing at least a period start time and a period end time during which radio modem  610  may either be permitted or prevented from executing a communication activity. The ability to include multiple allowed/disallowed periods into a single message packet  900  may support MRC  600  in scheduling radio modem behavior for longer periods of time, which may result in a reduction in message traffic. Further, changes in radio modem  610  activity patterns may be amended using the validity information in each message packet  900 . 
   The modem activity control signal (e.g., packet  900 ) is transmitted by MRC  600  to a specific radio modem  610 . The signal may include activity periods for Tx and Rx separately, and the periodicity of the activity for the radio modem  610 . While the native radio modem clock is the controlling time domain (never overwritten), the time reference utilized in synchronizing the activity periods to current radio modem operation may be based one of at least two standards. In a first example, a transmission period may start after a pre-defined amount of synchronization events have occurred in radio modem  610 . Alternatively, all timing between radio modem  610  and MRC  600  may be standardized around the system clock for MCS  700 . Advantages and disadvantages exist for both solutions. Using a defined number of modem synchronization events is beneficial because then all timing is closely aligned with the radio modem clock. However, this strategy may be more complicated to implement than basing timing on the system clock. On the other hand, while timing based on the system clock may be easier to implement as a time standard, a conversion to modem clock timing must necessarily be implemented whenever a new activity pattern is put into use in radio modem  610 . 
   As stated above, the activity period may be indicated as start and stop times. If there is only one active connection, or if there is no need to schedule the active connections, the modem activity control signal may be set always on allowing the radio modems to operate without restriction. The modem should check whether the transmission or reception is allowed before attempting the actual communication. A resynchronization may be initiated by the radio modem  610  if the transmission is consecutively blocked. The same happens if a radio modem time reference or connection mode changes. A problem may occur if MRC  600  runs out of the modem synchronization and starts to apply modem transmission/reception restrictions at the wrong time. Due to this, modem synchronization signals need to be updated periodically. The more wireless connections that are active, the more accurate MRC synchronization information needs to be. 
     FIG. 10  discloses a pictorial example of timing patterns between various active radio modems. Modems  1 ,  2  and  3  all have individual patterns that indicate when a modem is actively transmitting and/or receiving information. One example of a period wherein a possible conflict exists is highlighted in the figure. At this point MRC  600  may act to control various radio modems  610  in order to avoid the conflict. If the activity is to be restricted, MRC  600  configures the modem activity control message so that activity is always denied when radio modem  610  is not allowed to transmit or receive. The restriction can last either the whole period or just an individual transmission/reception instance. In the latter case, the activity can be allowed for some other transactional instance inside the period and radio modem  610  can utilize this to transmit (e.g. to attempt retransmission). 
   Radio modem  610  can indicate to MRC  600  the radio activity periods that were blocked due to the modem activity control message. This additional communication can be as a safety procedure to ensure that MRC  600  is not continuously blocking the communications due to off synchronization conditions. Radio modem  610  can switch off the transmitter/receiver every time the modem activity control signal is not allowing communication. Because the modem activity control signal is transmitted in advance and it provides information about the allowed and disallowed radio transmission/reception instances in the near future, radio modem  610  can prepare its operations in advance according to the activity control signal. Inside the validity parameter in the activity control message is a field describing whether the new message is replacing or added to the existing activity periods, thus avoiding the need to communicate the full transmission/reception pattern if only minor modifications are needed to correct the operation of the transmitter/receiver. 
   A flowchart describing an exemplary process where MRC  600  requests synchronization information from a radio modem in accordance with at least one embodiment of the present invention is disclosed in  FIG. 11 . In step  1102 , the application layer of WCD  100  triggers activation of a communication service. This activation may occur, for instance, due to a manual intervention by user  110  directly activating the communication service, or may instead be triggered indirectly by an application currently being manipulated by user  110 . WCD  100  may then activate the service in step  1104 . Various subsystems of WCD  100  are notified of the service activation, including MRC  600  (step  1106 ) which in turn requests clock synchronization information from radio modem  610  via MCS  700  in step  1108 . The synchronization request remains active until MRC  600  has received the signal and is synchronized (step  1110 ). In step  1112 , MRC  600  monitors for other radio modem activations, wherein a synchronization signal would need to be requested, or for changes in existing modem behavior. A detected change in radio modem behavior, for example during a handover or handoff, would be detected due to radio modem  610  itself prompting the delivery of synchronization information in step  1114 , and so new synchronization information is delivered to MRC  600 . 
     FIG. 12  includes an example of a process wherein MRC  600  monitors active radio modems and implements scheduling in order to avoid conflicts. In step  1202 , MRC  600  monitors a plurality of active radio modems. During this monitoring, MRC  700  may further recognize that at least some of the plurality of modems are about to act simultaneously which may result in a potential conflict (steps  1204  and  1206 ). MRC  600 , which has hierarchical information about the various mediums serviced by the radio modems, may then prioritize the radio modems in order to determine which modems to disable (step  1208 ). In step  1210 , MRC  600  transmits disable commands to various modems, essentially pausing the activity of these modems over designated time periods in order to avoid potential conflicts. This information may also be transmitted to the master control system in step  1212  in order to notify of temporary delays due to conflict avoidance, which might otherwise be deemed to be radio modem inoperability. Finally, in step  1214 , MRC  600  reactivates all modems once the potential conflict has passed, and resumes monitoring for possible communication conflicts. 
   VI. Method for Sending Information Over the MCS Interface. 
   An example of at least one embodiment of the process by which communications are managed in MCS  700  is disclosed in  FIG. 13A . In this example, two radio modems  610  are interacting with MRC  600 . Radio modem  1  is actively transmitting information on MCS  700 . Radio modem  2  also has information to deliver, but is monitoring MCS  700  through its MCS interface  710  in order to determine when communications become available. While the following examples use the specific elements of the present invention to describe a process of delay-sensitive communication, this communication method may be employed or implemented in any application wherein information that is time or delay sensitive must be correlated to a specific instance of creation regardless of the actual time of receipt. 
   MCS  700  may be implemented utilizing a variety of bus structures, including the I 2 C interface commonly found in portable electronic devices, as well as emerging standards such as SLIMbus that are now under development. I 2 C is a multi-master bus, wherein multiple devices can be connected to the same bus and each one can act as a master by initiating a data transfer. An I 2 C bus contains at least two communication lines, an information line and a clock line. When a device has information to transmit, it assumes a master role and transmits both its clock signal and information to a recipient device. SLIMbus, on the other hand, utilizes a separate, non-differential physical layer that runs at rates of 50 Mbits/s or slower over just one lane. It is being developed by the Mobile Industry Processor Interface (MIPI) Alliance to replace today&#39;s I 2 C and I 2 S interfaces while offering more features and requiring the same or less power than the two combined. In an exemplary embodiment of the present invention using the I 2 C interface, any of the devices on MCS  700  may initiate communication with another device, with the clock signal correlated to radio modem  610 , as previously indicated (so as not to alter or disrupt the timing of the radio modems), the system clock, or an internal clock synchronized using one of the two previous standards. 
   In  FIG. 1   3 A, radio modem  1  is transmitting delay sensitive status information to MRC  600 . Radio modem  1  may initially check MCS  700  to determine availability. After verifying that MCS  700  is free for communication, radio modem  1  may begin generating a clock signal to the communication bus and initiate message transmission to MRC  600 . In the present example, four (4) clock pulses after the transmission commences radio modem  1  receives confirmation from MRC  600  that the full message has been received (“message complete”).  FIG. 13A  shows that it took a total duration of four ( 4 ) clock pulses to transmit the message, which is appended to the end of the received message (shown as the value “4” under “count”). 
   However, the message received from radio modem  1  has not yet been processed in MRC  600 . In some cases, MRC  600  may be busy with other tasks and may not be available to immediately process a received message. The counter in MRC  600  may reset upon message receipt and will then resume counting based on the clock signal generated by radio modem  1  (or, for example, by its own internal clock) until the message is able to be processed. An additional five (5) counts occur before MRC  600  completes the prior task(s) and becomes available to process the received message. This waiting count is also appended to the message before processing. The purpose of appending the various count values to the received message is to allow MRC  600  to determine when the message was first created with respect to the clock signal provided by radio modem  1 . As previously indicated, the received message is time sensitive, and therefore, it may be important for MRC  600  to determine the initial creation time of the message so that an appropriate response (e.g., an activity control message to modem  1 ) may be composed and sent. 
   Radio modem  2  also has information to transmit to MRC  600 . However, radio modem  1  is currently occupying MCS  700 , and so radio modem  2  must wait for MCS  700  to become available. At the instant that radio modem  2  has a message to send, its internal clock and delay counter may start. This clock signal will not be broadcast on MCS  700 . Instead, modem  2  will internally track the time that passes (e.g., by counting the clock pulses) until the radio modem  2  can transmit, which is further depicted in  FIG. 13B . 
   In  FIG. 13B , radio modem  1  has completed communications on MCS  700 , allowing radio modem  2  to utilize MCS interface  710  to communicate on MCS  700 . As soon as the bus becomes available, radio modem  2  may append the delay counter value to the outgoing message packet. In the figure, “118” has initially been appended to the message to represent the time that radio modem  2  waited from the time of message creation until MCS  700  became available. Now that MCS  700  is available, radio modem  2  may transmit a message to MRC  600 . In the present example, a confirmation of receipt message is received in radio modem  2  after three (3) counts. As a result, “3” is also appended to the message received in MRC  600 . As explained above, MRC  600  will, in some instances, be occupied with other tasks that delay the processing of the message received from radio modem  2 . In this example an additional four (4) counts are recorded before the message can be processed by MRC  600 , and this additional value is also appended to the message before processing. MRC  600  may use the appended count information, along with the clock signal provided by radio modem  2 , to determine when the message was originally created by the radio modem. 
   The information provided by radio modems  1  and  2  above is considered by MRC  600  in view of priority policies and/or rules when determining an appropriate operational schedule for each of the plurality of radio modems  610  in WCD  100 . Once an operational schedule is determined, MRC  600  may respond to any or all of radio modems  610  with various activity control messages based on the timing of each radio modem. A control message initiated by MRC  700  to any of the radio modems  610  may use the clock values previously recorded from the radio modem status messages described above, or alternatively, MRC  600  may request an updated clock value from a radio modem  610  in order to reorient its internal timing. 
   While a transaction wherein a radio modem  610  transmits time sensitive information to MRC  600  has been previously described, communication traveling in the other direction is also anticipated by the present invention. In an exemplary case where MRC  600  has information to send to one or more radio modems  610  (e.g., activity control information, a request for synchronization, etc.) MRC  600  may initiate communications to any other device on MCS  700  using MCS interface  720 . The creation of a message may trigger delay and/or transmission counters that accumulate until a “message complete” acknowledgement is received from the target device. The counter information may be appended to the message at each stage of message transmission. In this way, a recipient device can determine when the message was originally created in view of delays such as MCS  700  being occupied by other communication traffic, retransmission of the message due to a communication error, etc. 
     FIG. 14  discloses an exemplary flowchart detailing an MCS communication process in accordance with at least one embodiment of the present invention. In step  1400 , the communication logic of a transmitting device receives notification of data to be transmitted to another device through MCS  700 . The transmitting device may then begin to generate a clock signal (step  1402 ). In step  1404 , the transmitting device determines whether MCS  700  is available If the communication bus is occupied, then the transmitting device does not broadcast its clock signal, but starts a delay timer in step  1406  to record the time spent waiting for MCS  700  to become available. When MCS  700  is free, the delay timer value may then be appended to the message packet by the transmitting device, and if the message is successfully transmitted and an acknowledgement as received, the counter can be reset (step  1408 ). In cases where MCS  700  is immediately available, the delay timer value will often be zero ( 0 ). The transmitting device may then initiate sending the message to MRC  600 . A counter in the receiving device may start counting in step  1410  until a “message complete” confirmation is received from the destination receiving device in step  1412 . When the confirmation is received at the destination device, the current value of the counter in receiving device is appended to the received message representing the time it took to transmit the message, and then the counter may reset for the next event (step  1414 ). 
   In step  1416  a waiting counter begins to keep track of the duration starting from the time the message is successfully received in the receiving device until the time the message is processed. The receiving device may be occupied with other tasks that must be completed before processing the received message. The waiting counter will continue to accumulate counts until the receiving device (e.g., the software further processing the received message) is available (step  1418 ). When the receiving device is available, the value of the waiting timer is either appended to the received message before processing, or the software can read the counter value directly from the counter in step  1420 . As a result of this process, three timer values (the delay timer, the transmission timer and the waiting timer) may be considered by the receiving device when determining the original creation time of the message in view of the clock signal provided by the sending device (step  1422 ). The transmission timer and the waiting timer can be physically the same units since both may be located in MRC  600  and not accumulated simultaneously. The process then starts over at step  1400  when a device on MCS  700  has another message to transmit. 
   The present invention is an improvement over the state of the art. The multipoint control system of the present invention allows a device with a plurality of active radio modems to efficiently manage communications between these modems in order to avoid potential communication conflicts. This scheduling of wireless communication resources allows a wireless communication device to function in a fully enabled mode without experiencing communication quality degradation due to the constant retransmission of lost packets. The result is a fully enabled wireless communication device that satisfies user expectations because interactivity does not suffer as the device is fully deployed in more complex applications. 
   Accordingly, it will be apparent to persons skilled in the relevant art that various changes in form a and detail can be made therein without departing from the spirit and scope of the invention. The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.