1. Field of the Invention
Example embodiments of the present application relate to a system and method for telecommunications. More particularly, example embodiments are directed to system and methods for more efficiently using the capacity of a control channel.
2. Background Information
Wireless communication systems enable people to communicate with one another over distances without having to necessarily access landline-connected devices such as conventional telephones. Early wireless communication systems were primarily configured for voice communications. However, technological improvements have enabled the development of third generation (3G) and similar wireless networks for both voice and high-speed packet data transfer such as Code Division Multiple Access (CDMA) Evolution Data Optimized or Evolution Data Only (1xEV-DO) systems, for example, are now implemented in many parts of the United States. Elsewhere, CDMA2000.RTM. 3G mobile telecommunications protocol/specification is being used for the high-speed wireless transmission of both voice and non-voice data.
Much of the focus in developing the above mentioned wireless communication networks have focused on improving the use of traffic channels. The use and capacity of control channels and signaling over the control channels used to establish the traffic channels have largely been ignored because the amount of time required for paging an access terminal is generally small compared to the amount of time of an average voice call conducted over a traffic channel. For example, the amount of time for paging an access terminal may be several orders of magnitude less than the time duration of an average voice call. Thus, conventionally, the capacity of the traffic channel has been considered by many as the limiting factor and thus, the control channel capacity has largely been ignored.
Example embodiments of the present application are directed towards efficient use of control channels of a wireless communication system.
Example embodiments of the present application are directed towards increasing capacity of the control channel.
An example embodiment relates to a wireless communication system. The wireless communication system includes a network and a plurality of access terminals. The plurality of access terminals includes a first group of access terminals configured to receive control information at a first data rate and send a response to the received control information, as well as a second group of access terminals configured to receive the control information at a second data rate and send a response to the received control information. The second data rate is higher than the first data rate. The network is configured to send the control information via a control channel at the first data rate and the second data rate, receive responses from the plurality of access terminals, and establish a traffic channel with at least one of the plurality of access terminals based on the control information and associated response from at least one of the plurality of access terminals.
An example embodiment provides a wireless communication method. The wireless communication method includes sending control information at a first data rate via a control channel to at least one first access terminal; and sending control information at a second data rate via the control channel to at least one second access terminal. The second data rate is higher than the first data rate.
According to an example embodiment, the method may also include receiving responses from the at least one first access terminal and the at least one second access terminal; and establishing a traffic channel with at least one of the at least one first access terminal and the at least one second access terminal based on the control information and the received responses.
Another example embodiment provides a wireless communication method. The wireless communication method includes sending control information to an access terminal at multiple different data rates over a control channel; receiving a response from the sent control information; and establishing a traffic channel with the access terminal based on the control information and received response. The control information including at least one Medium Access Control (MAC) packet sent at a first data rate and at least one other MAC packet sent at a second data rate. The second data rate is higher than the first data rate.
Still a further example embodiment provides a wireless communication method. The wireless communication method includes receiving control information from a network at multiple different data rates via a control channel; transmitting a response to the network in response to receiving the control information; and establishing a traffic channel with the network based on the received control information. The control information including at least one first Medium Access Control (MAC) packet sent at a first data rate and at least one second MAC packet sent at a second data rate. The second data rate is higher than the first data rate.
Another example embodiment provides a wireless communication method. The wireless communication method includes providing a control channel for communicating data to an access terminal at multiple different data rates. The control includes at least one first Medium Access Control (MAC) packet sent at a first data rate and at least one second MAC packet sent at a second data rate. The second data rate is different than the first data rate.
An example embodiment provides an enhanced control channel. The enhanced control channel includes a plurality of Medium Access Control (MAC) packets, and the plurality of MAC packets includes at least one first MAC packet with control information provided at a first data rate and at least one second MAC packet with control information provided at a second data rate. The second data rate is different than the first data rate.
The above and other features and advantages of example embodiments will become more apparent by reviewing the following detailed description of example embodiments of this disclosure with reference to the attached drawings in which:
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc., in order to provide a thorough understanding of example embodiments. However, it will be apparent to those skilled in the art that example embodiments may be practiced in other illustrative embodiments that depart from these specific details. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of example embodiments with unnecessary detail. All principles, aspects, and embodiments, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future.
Example embodiments are discussed herein as being implemented in a suitable computing environment. Although not required, example embodiments will be described in the general context of computer-executable instructions, such as program modules or functional processes, being executed by one or more processors or CPUs. Generally, program modules or functional processes include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The program modules and functional processes discussed herein may be implemented using existing hardware in existing communication networks. For example, program modules and functional processes discussed herein may be implemented using existing hardware at existing radio network control nodes.
In the following description, illustrative embodiments will be described with reference to acts and symbolic representations of operations (e.g., in the form of flow charts) that are performed by one or more processors, unless indicated otherwise. As such, it will be understood that such acts and operations, which are at times referred to as being computer-executed, include the manipulation by the processor of electrical signals representing data in a structured form. This manipulation transforms the data or maintains it at locations in the memory system of the computer, access terminal, base station transceiver station, radio network controller, etc., which reconfigures or otherwise alters the operation of the computer, access terminal, radio network controller and/or base station transceiver station in a manner well understood by those skilled in the art.
Example embodiments are directed at least in part to increasing capacity of a control channel. Stated differently, example embodiments are directed at least in part to efficient use of the capacity of a control channel. Further, example embodiments are directed towards an enhanced control channel for providing control information at multiple data rates.
Referring to
As shown in
Referring to
Still further, the first MAC packets 3000, the second MAC packet 3100 and the third MAC packet 3200 may be formatted differently. For example, the first MAC packets 3000 may be wrapped with a MAC index that is different from the index of second MAC packet 3100 and the third MAC packet 3200. As such, the wrapping of the MAC packets with a MAC index may be used by the access terminals to derive implicit information about the MAC packets and/or control information being sent in the form of the MAC packets. The implicit information includes rules relating to a protocol of an access terminal such as decoding information, Walsh codes, and a MAC ID of control channels, for example.
One skilled in the art will appreciate that
Referring to
The wireless communication system shown in
As described herein, example embodiments of the enhanced access terminals 100 are configured for receiving control information at multiple data rates. For example, an enhanced access terminal 100 may receive control information at both a first data rate of 76.8 kbits/second (kbps) and a second data rate of 307.2 kbps via an enhanced control channel as described with respect to
The enhanced access terminals 100 and the legacy access terminal 200 may include a transceiver, memory and processor. For example, the enhanced access terminal 100 shown in
The plurality of BTSs 300 provides communications between the RNC 400 and the plurality of access terminals including the enhanced access terminals 100 and the legacy access terminals 200. Each of the BTSs 300 has a service area or cell, and communicates with the access terminals within this service area or cell. As such, when the RNC 400 attempts to establish a traffic channel with one or more of the access terminals, the RNC 400 sends control information including paging information over an enhanced control channel. The control information including paging information may be sent through the plurality of BTSs 300 in order to locate the desired access terminal and determine which of the plurality of BTSs 300 may be used to communicate with the desired access terminal. Each of the BTSs 300 includes a transceiver 301, a memory 303 and a processor 305. The transceiver 301 is configured to receive communications from one or more of the RNC 400 and the access terminals 100 and 200, as well as transmit information to one or more of the RNC 400 and the access terminals 100 and 200. The memory 303 stores information used and/or required by the BTSs 300. For example, the memory 303 may store information about access terminals receiving information or services from the Internet 600, AAA 700 and/or BCMCS 800 via the PDSN 500 and RNC 400. The processor 305 of each BTS 300 controls operations of the BTS 300, causes information to be stored in the memory 303, and/or controls reception and transmission of communications performed by the transceiver 301.
Still referring to
According to an example embodiment, the RAN 350 includes information for access terminals identifying the access terminals as enhanced access terminals 100 or legacy access terminals 200. This information may be obtained during configuration negotiations of an access terminal, idle transfer of an access terminal, or during an authentication, authorization or accounting process of an access terminal. Idle transfer refers to when an access terminal moves from a coverage area of one RNC 400 to another RNC 400 without call on and will be understood by one skilled in the art. For example, this information identifying access terminals as enhanced access terminals 100 or legacy access terminals 200 is stored in the memory 403 and/or the memory 303 both of which are shown in
Still referring to
As previously mentioned, example embodiments are directed towards communicating control information at multiple different data rates via an enhanced control channel. Accordingly, example operations and/or functions performed by various components of the wireless communication system will now be described with reference to
As previously described with respect to
As such, each MAC packet may include information such as an access terminal identifier used to page a designated access terminal. An access terminal may determine if control information communicated via the control channel is designated for the access terminal by reviewing information included in a communicated MAC packet. For example, a legacy access terminal 200 may review the control information included in a MAC packet for an identifier identifying the legacy access terminal 200 as the designated access terminal. The identifier may be included in a MAC packet header 3010, for example. If the legacy access terminal 200 does not find the correct identifier in a received MAC packet, the legacy access terminal 200 ignores the received MAC packet. Alternatively, if the legacy access terminal 200 does find the correct identifier, the legacy access terminal 200 processes the MAC packet and responds accordingly. As another example, an enhanced access terminal 100 may review the control information included in a MAC packet for an identifier identifying the enhanced access terminal 100 as the designated access terminal. If the enhanced access terminal 100 does not find the correct identifier in a received MAC packet, the enhanced access terminal 100 ignores the received MAC packet. Further, if the enhanced access terminal 100 does find the correct identifier, the enhanced access terminal 100 processes the MAC packet and responds accordingly.
Example embodiments of methods performed by a network are described below with respect to the flowcharts of
Referring to
According to one example of a legacy protocol associated with the legacy access terminal 200, if a bit included in a last packet field is a ‘1’, for example, the legacy access terminal 200 identifies the ‘1’ included in the last packet field of the MAC packet 3000. In response to receiving and identifying the ‘1’ in the last packet field, the legacy access terminal 200 stops monitoring information received on the control channel following reception of the MAC packet 3000 including the ‘1’ in the last packet field until a next scheduled cycle. Alternatively, if the bit in the last packet field of the MAC packet 3000 is a ‘0’, the legacy access terminal 200 will continue monitoring the control channel for following MAC packets in accordance with the protocol associated with the legacy access terminal 200.
In step S110, the RAN 350 sends control information at a second data rate to enhanced access terminals 100. The second data rate is higher than the first data rate. For example, the second data rate may be 307.2 kbps. This control information is sent in a MAC packet 3100 shown in
In step S120, a transceiver of the RAN 350 such as the transceiver 401 of the RNC 400 receives responses to the control information sent at one or more of the multiple data rates to an access terminal of the wireless communication system shown in
The responses from the various different access terminals may then be processed by the RAN 350 and one or more traffic channels are established with the legacy access terminal 200 and/or the enhanced access terminals 100 based on the control information transmitted to the respective access terminals and responses received from the respective access terminals as illustrated by step S130 of
In step S210 of
In response to receiving the control information, the processor 105 of the enhanced access terminal 100 processes the received control information in step S220. In particular, the processor 105 may first review the control information for an identifier associated with the specific enhanced access terminal 100 indicating the received control information is designated for the enhanced access terminal 100. Further, the processor 105 processes the control information to determine if and what form of traffic channel and/or communication is to be expected from the network.
According to an example embodiment, the control information received from the network may be in the form of a MAC packet 3000 or 3100 and may include a plurality of indicators and/or information, which are used by the processor 105 of the access terminal 100 to process the received control information. For example, if a first MAC packet 3000 is transmitted at a first data rate of 76.8 kbps and includes an indicator indicating the MAC packet is the last MAC packet for a legacy access terminal 200, the processor 105 of an enhanced access terminal 100 may interpret this indicator as instructing the enhanced access terminal 100 to continue monitoring the control channel for second MAC packets 3100 transmitted and the second data rate of 307.2 kbps, for example.
It is noted that, according to an example embodiment, the bit included in the last packet field may be interpreted differently by enhanced access terminal 100 than the same indicator would be interpreted by a legacy access terminal 200. For example, in response to receiving a MAC packet 3100 at the second data rate, which includes a ‘1’, the processor 105 of the enhanced access terminal will continue monitoring the control channel, whereas the legacy access terminal 200 would discontinue monitoring the control channel. Further, because the MAC packet 3100 is transmitted at a higher data rate, additional control information may continue to be provided to the enhanced access terminal 100 and the communication of this additional control information will require less control channel resources since the MAC packet 3100 is transmitted at a higher data rate and uses a format that reduces the number of slots needed for its transmission.
Referring to step S230 of
In step S240 of
As previously mentioned, example embodiments are directed towards increasing capacity of the control channel and/or efficient use of the capacity of a control channel. As wireless communication systems continue to evolve, the use of the control channel capacity is becoming increasingly important. Whereas a typical voice call may last hundreds of seconds, a push-to-talk communication or transfer of a data file from the Internet may only require seconds of communications via a traffic channel. For example, if the communication only requires 20 seconds of a traffic channel, the paging time duration to data transfer time duration ratio is 1 to 200. Accordingly, the paging channel could become a limiting factor.
The specific example described below further illustrates features of the various example embodiments described above. In this example, the first data rate is 76.8 kbps and 25% of the capacity of the control channel is occupied for paging legacy access terminals 200. If the second data rate is 307.2 kbps, enhanced access terminals 100 are paged approximately four times faster than legacy access terminals 200 since 307.2 kbps is approximately four times faster than 76.8 kbps. Stated differently, paging the enhanced access terminals at 307.2 kbps requires about four times fewer of the number of available slots in the control channel. Assuming 90% of the access terminals are enhanced access terminals 100 being served are provided control information at the second data rate of 307.2 kbps, the slot occupancy for these enhanced access terminals 100 for 90% of the users can be roughly calculated as (25/4) plus 0.1×25=8.75% or about 9% of the slots in one control channel cycle.
Example embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the example embodiments, and all such modifications are intended to be included within the scope.