Patent Application
20120003969
The present disclosure relates generally to group calls in communication systems and more particularly to a method and apparatus for establishing a group call in a communication system.
Various real time situations require a group call setup in a communication system to enable users in different geographical locations having varying signal conditions to communicate at the same time. One method to quickly setup a group call is by using unicast bearers i.e. each user will have an uplink and a downlink logical channel pair for participating in the group call. In a Long Term Evolution (LTE) system the typical initial setup time for a unicast call ranges from one hundred to five hundred milli seconds (100-500 msecs). However, using an uplink and a downlink logical channel pair for each user in the group call consumes a lot of frequency spectrum.
An alternative method for setting up a group call is by using broadcast or multicast bearers for users within a preconfigured broadcast or multicast region such as multimedia broadcast over single frequency network (MBSFN) area. In this method each user will have individual uplink channels and a common downlink channel, thereby reducing the number of communication links used for the group call. However, the approximate call setup time in this case is typically around one to five seconds (1-5 secs). In other words, although the alternative method increases the spectral efficiency of the communication system, the method has an increased initial call setup time. Further, the alternative method describes group call setup based on preconfigured regions and does not describe continuing the group call when the users move from one place to another.
Accordingly, there is a need for a method and apparatus for establishing a group call.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
A method, device, and system for quickly establishing a group call among a plurality of communication devices by using unicast bearer services and then switching the group call to multicast bearer services after the system has instantiated the multicast services is described herein.
In accordance with one embodiment, a method, device, and system for establishing a group call among a plurality of communication devices is described herein. The system includes a plurality of communication devices serviced by their respective base stations and a control entity for communicating with the base stations. The system further includes at least some of the plurality of communication devices participating in the group call using unicast communication links. In accordance with some embodiments, the control entity computes one or more broadcast or multicast parameters during the group call, identifies a subset of communication devices based on the broadcast or multicast parameters, and switches the identified subset of communications devices to a broadcast or multicast communication link during the group call.
Referring now to figures,
Referring to
As used herein, eNodeBs 115 and 125 are infrastructure devices that can communicate information in a wireless signal with the RAN controller 130 using a logical channel pair comprising an uplink or reverse 137-1 and 137-2 logical channel and downlink or forward 135-1 and 135-2 logical channel, respectively. The eNodeBs 115 and 125 can also receive information from one or more UEs 112-1, 112-2 . . . 112-n and 122-1, 122-2 . . . 122-n via logical uplink channels 116-1 . . . 116-n and 126-1 . . . 126-n, respectively. Further, the eNodeBs 115 and 125 can transmit information to one or more UEs 112-1, 112-2 . . . 112-n and 122-1, 122-2 . . . 122-n via logical downlink channels 114-1 . . . 114-n and 124-1 . . . 124-n, respectively. An eNodeB 115, 125 includes, but is not limited to, equipment commonly referred to as base transceiver stations, access points, routers or any other type of UE interfacing device in a wireless environment.
Returning to
In
Referring back to
Only a limited number of eNodeBs 115, 125 and UEs 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n are shown for ease of illustration. However, the communication system 100 can include any number of eNodeBs to support any number of UEs based on system requirements. Moreover, embodiments are not dependent on the protocol(s) used to facilitate communications in the system and can be used with any such protocols.
In general, the communication links (also referred to herein as communication channels or channels) comprise the physical communication resources over which information is sent between different elements in the communication system 100 and can include wired links (e.g., links 139-1 and 139-2) or wireless links (e.g., 135-1, 135-2, 137-1, 137-2, 114-1 . . . 114-n, 116-1 . . . 116-n,124-1 . . . 124-n, and 126-1 . . . 126-n) with a wireless interface between the equipment in the communication system 100 being defined by the protocols implemented in the communication system 100. For example, as illustrated in
In a LTE/EUTRA system, each logical channel pair (uplink and downlink pair), e.g., 114-116 and 124-126 constitutes frequency division duplexed (FDD) or time division duplexed (TDD) physical layer channels (frequency channels). The downlink or forward channel includes physical layer channels transmitted from the LTE/EUTRA to the user equipments, wherein the forward channel is also capable of supporting broadcast and multicast of control information and media information such as but not limited to audio media, video media, data media, and multimedia. The uplink or reverse channel includes the physical layer channels transmitted from the user equipments to the LTE/EUTRA.
The embodiments are described in the context of an LTE/EUTRA system for ease of illustration. However, the embodiments are not limited to such a system but can be applied within any other system that employs multiple carrier frequencies for multiple services.
The processor 205 includes one or more microprocessors, microcontrollers, DSPs (digital signal processors), state machines, logic circuitry, or any other device or devices that process information based on operational or programming instructions. Such operational or programming instructions are stored in the memory 230. The memory 230 can be an IC (integrated circuit) memory chip containing any form of RAM (random-access memory) or ROM (read-only memory), a floppy disk, a CD-ROM (compact disk read-only memory), a hard disk drive, a DVD (digital video disc), a flash memory card, external subscriber identity module (SIM) card or any other medium for storing digital information. One of ordinary skill in the art will recognize that when the processor 205 has one or more of its functions performed by a state machine or logic circuitry, the memory 230 containing the corresponding operational instructions can be embedded within the state machine or logic circuitry. The operations performed by the processor 205 and the other elements of the communication device 200 are described in detail below.
The transmitter circuitry 215 and the receiver circuitry 220 enable the communication device 200 to communicate radio signals to and acquire signals from the eNodeBs 115 and 125. In one embodiment, the transmitter circuitry 215 and the receiver circuitry 220 enable the communication device 200 to communicate radio signals to and acquire signals from the UEs 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n. In this regard, the transmitter circuitry 215 and the receiver circuitry 220 include appropriate, conventional circuitry to enable digital or analog transmissions over a wireless communication channel. The implementations of the transmitter circuitry 215 and the receiver circuitry 220 depend on the implementation of the communication device 200. For example, the transmitter circuitry 215 and the receiver circuitry 220 can be implemented as an appropriate wireless modem, or as conventional transmitting and receiving components of two-way wireless communication devices. In the event that the transmitter circuitry 215 and the receiver circuitry 220 are implemented as a wireless modem, the modem can be internal to the communication device 200 or insertable into the communication device 200 (e.g., embodied in a wireless radio frequency (RF) modem implemented on a Personal Computer Memory Card International Association (PCMCIA) card or a universal serial bus (USB) card). For a wireless communication device, the transmitter circuitry 215 and the receiver circuitry 220 are implemented as part of the wireless device hardware and software architecture in accordance with known techniques. One of ordinary skill in the art will recognize that most, if not all, of the functions of the transmitter circuitry 215 and/or the receiver circuitry 220 can be implemented in a processor, such as the processor 205. However, the processor 205, the transmitter circuitry 215, and the receiver circuitry 220 have been artificially partitioned herein to facilitate a better understanding.
The receiver circuitry 220 is capable of receiving radio frequency (RF) signals from at least one frequency band and optionally multiple frequency bands, when, for example, the communications with a proximate device are in a frequency band other than that of the system communications. The transceiver 210 includes one set of transmitter circuitry 215. The antenna 225 comprises any known or developed structure for radiating and receiving electromagnetic energy in the frequency range containing the wireless carrier frequencies. The communication interface 245 uses transceiver 210 to enable the communication device 200 to communicate with other devices and/or systems. For example, the communication interface 245 may include mechanisms for communicating with another device or system via a back bone network 150 as shown in
As illustrated in
In one embodiment, the UEs 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n, having a link parameter value or a location parameter value within a predefined range, are grouped together. The link parameter 235 and location parameter 240 are periodically received from all the UEs 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n participating in the group call. The communication device 200 receives the link parameter 235 and the location parameter 240 from the UEs through the transceiver circuitry 210 and the uplink channels 137-1 and 137-2, 116-1 . . . 116-n, and 126-1 . . . 126-n. In one embodiment, the communication device 200 also receives link and location parameters from communication devices other than the UEs 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n in the communication system 100. The communication devices can be wired or wireless devices. The communication device 200 receives the parameters from the wired communication devices through the communication interface 245.
The method 400 further includes the RAN controller 130 monitoring 430 a set of link and location parameters associated with each of the participating UEs. 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 during the group call. The monitored link parameters include, but not limited to a received signal strength indication (RSSI) value, a carrier to interference plus noise ratio (CINR) associated with downlink logical channel 114 and data traffic on the unicast communication link (uplink 116, 126 and downlink 114, 124 logical channel pair). The monitored location parameter includes a geographical location such as, latitude, longitude, and altitude, of the participating UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2.
Referring back to the method 400 the RAN controller 130 determines 440 whether the link parameter value for each of the participating UEs (one of 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2) is within a predefined range of values. When the link parameter values associated with the UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 are within a predefined range, the RAN controller 130 proceeds with determining 450 whether the location parameter value for each of the participating UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 is within a predefined location range. If the location parameter values associated with the UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 are within the predefined location range then the UEs are grouped to form 460 a subset for broadcast or multicast communication. The subset can also be called as a dynamically formed MBSFN area or zone 160. On the other hand, if the link parameter values associated with the UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 are not within a predefined range the UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 continue 480 the group call using unicast communication links. The communication devices continue with the group call until a group call termination signal is received from any one of the communication devices, for example 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n, 115, 125, and 130, participating in the group call.
In one example, a downlink CINR associated with all the UEs 112-1, 112-2, 112-3, 112-n, 122-1, and 122-2 participating in the group call is measured. If the UEs for example 112-1, 112-2, 122-1, and 122-2, as shown in
For the ease of illustration only a set of UEs are shown to form the subset. However, UEs other than the above mentioned UEs can be a part of the subset. Also, when the UEs move during the group call their association with the subset can change and can lead to the formation of a new subset for multicast communication or a new MBSFN zone. The newly formed MBSFN zone can include the previous set of UEs along with some new UEs or the new MBSFN zone can include a completely different set of UEs.
The method 400 iterates by monitoring 430 periodically the link and location parameters from the UEs participating in the group call and performing the steps of determining 440 through switching 470. In one example, the iteration stops with a group call termination signal from any one of the communication devices 112-1, 112-2 . . . 112-n, 122-1, 122-2 . . . 122-n, 115, 125, and 130 participating in the group call.
In one another embodiment, the RAN controller 130 monitors a spectral efficiency associated with the group call. The spectral efficiency can be determined based on the link parameters associated with the UEs participating in the group call. Based on the spectral efficiency the RAN controller 130 can determine whether to switch the UEs to a broadcast or multicast link or to continue a particular UE with the unicast communication link, during the group call.
Upon receiving the link and location parameters from the eNodeBs 115 and 125 the RAN controller 130 identifies UEs for unicast, multicast, and broadcast communication, based on the link and location parameters. The RAN controller 130 then sends control instructions 530 to the eNodeBs 115, 125 to switch at least some of the identified UEs to use a broadcast or multicast communication link. In one example, as illustrated in
In one embodiment, when the RAN controller 130 identifies that a particular UE or a group of UEs is serviced by at least two eNodeBs 115 and 125 a simulcast transmission is enabled in the communication system 100. The RAN controller 130 instructs both the eNodeBs 115 and 125 to simulcast transmission to the particular UE or the group of UEs. Simulcast transmission is defined as transmission of same data or information to the particular UE or the group of UEs from all the eNodeBs serving the particular UE or the group of UE at the same frequency and at the same instant of time. In one embodiment, the same data or information is simultaneously transmitted from both the eNodeBs 115 and 125 to the particular UE using a unicast communication link. In another embodiment, the same data or information can be simultaneously broadcast or multicast from both the eNodeBs 115 and 125 to the group of UEs through the broadcast or multicast communication link.
Advantages of the various embodiments include: enabling a faster call setup using unicast communication links and switching to a spectrally efficient multicast communication link during the call. This switching helps in reducing the number of unicast communication links used in the group call thereby effectively increasing the spectral efficiency of the group call. For example, in the prior art method, if twenty five users are participating in the group call, the system has to allocate twenty five unicast communication links or fifty logical frequency channels. With the present method, the system allocates the fifty logical frequency channels, only when the group call is started. During the group call, if all the twenty five users are found to be within a particular geographical area or having a predefined signal range, they will be grouped to form a subset for multicast communication. The multicast communication uses twenty five uplink logical channels and a single downlink logical channel. This reduces the number of logical frequency channels from fifty to twenty six. Thus the present method provides an optimized two step group call setup by starting with a quick unicast call and switching to a more spectrally efficient multicast call. In accordance with some embodiments the switching is also based on the mobility of the communication devices participating in the group call. This provides a dynamically optimized group call setup. Those skilled in the art will realize that the above recognized advantages and other advantages described herein are merely illustrative and are not meant to be a complete rendering of all of the advantages of the various embodiments.
In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.
The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
The present application is related to the following U.S. application commonly owned with this application by Motorola, Inc.: Ser. No. ______, filed Jun. 30, 2010, titled “METHOD AND APPARATUS FOR ESTABLISHING AND MAINTAINING A SPECTRALLY EFFICIENT MULTICAST GROUP CALL” (attorney docket no. CM13342), the entire contents of which being incorporated herein by reference.
