Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B7/00—Radio transmission systems, i.e. using radiation field
  • H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
  • H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
  • H04B7/2643—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA]
  • H04B7/2646—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA] for broadband transmission
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/56—Allocation or scheduling criteria for wireless resources based on priority criteria
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
  • H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
  • H04W16/06—Hybrid resource partitioning, e.g. channel borrowing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W24/00—Supervisory, monitoring or testing arrangements

Definitions

• the present invention relates generally to radiocommunication systems and, more particularly, to techniques and structures for the efficient use of silent periods in speech communication.
• IP Internet protocol
• Packet-switched technology which may be connection-oriented (e.g. , X.25) or "connectionless" as in IP, does not require the set-up and tear-down of a physical connection, which is in marked contrast to circuit-switched technology. This reduces the data latency and increases the efficiency of a channel in handling relatively short, bursty, or interactive transactions.
• a connectionless packet-switched network distributes the routing functions to multiple routing sites, thereby avoiding possible traffic bottlenecks that could occur when using a central switching hub. Data is "packetized" with the appropriate end-system addressing and then transmitted in independent units along the data path. Intermediate systems, sometimes called
• FIG. 1 shows representative architecture used for communicating across an air link that comprises the packet data protocols which provide connectivity between a mobile end system (e.g. , a mobile station), a mobile data base station (MDBS), and a mobile data intermediate system (MD-IS).
• a mobile end system e.g. , a mobile station
• MDBS mobile data base station
• MD-IS mobile data intermediate system
• IP/Connectionless Network Protocol are network protocols that are connectionless and widely supported throughout the traditional data network community. These protocols are independent of the physical layer and preferably are not modified as the RF technologies change.
• the Security Management Protocol provides security services across the air link interface.
• the services furnished include data link confidentiality, M-ES authentication, key management, access control, and algorithm upgradability /replacement.
• the SMP should remain unchanged when implementing alternative RF technologies.
• the Radio Resource Management Protocol provides management and control over the mobile unit's use of the RF resources.
• the RRMP and its associated procedures are specific to the AMPS RF infrastructure and require change based on the RF technology implemented.
• the Mobile Network Registration Protocol (MNRP) is used in tandem with a
• MNLP Mobile Network Location Protocol
• the Mobile Data Link Protocol provides efficient data transfer between the MD-IS and the M-ES.
• the MDLP supports efficient mobile system movement, mobile system power conservation, RF channel resources sharing, and efficient error recovery.
• the MDLP should be unchanged when using alternative RF technologies.
• the Medium Access Control (MAC) protocol and associated procedures control the methodology M-ESs used to manage shared access to the RF channel. This protocol and its functionality is supplied by alternative RF technologies.
• MAC Medium Access Control
• RT real time
• QoS Quality of Service
• Certain users, for example, those utilizing real time voice applications will have a very high demand for the availability of transmission resources, whereas users, for example, who transmit short messages or electronic mail, will be satisfied with a lower availability of transmission resources.
• RT real time
• QoS Quality of Service
• UMTS there are four proposed QoS classes: the conversational class; streaming class; interactive class; and background class.
• the main distinguishing factor between these classes is the sensitivity to delay of the traffic.
• Conversational class traffic is intended for traffic which is very delay sensitive while background class traffic is the most delay insensitive traffic class.
• Conversational and streaming classes are intended to be used to carry RT traffic flows and interactive and background classes are intended to be used to carry Internet applications (e.g. , WWW, E-mail, Telnet, FTP, etc.).
• Real time services include sensitive time constraints over a reserved access channel. That is, delays in the transmission and/or receipt of successive packets can have noticeable and undesirable QoS effects (e.g. , on voice quality).
• Silent periods can be detected in a Voice Activity Detector (VAD) device.
• VAD Voice Activity Detector
• a Silence Descriptor (SID) is sent to a receiver.
• the SID informs the receiver that a silent period has begun.
• the SID indicates the type of "comfort noise" which is to be generated at the receiver.
• the receiver generates comfort noise in order to closely mimic the naturally occurring background noise so that the receiving user perceives that the communication path between the transmitter and the receiver is still open and operable.
• an indication is sent to the transmitter that there is no voice activity detected and the transmitter can reduce its transmitter output power or set it to zero for that connection. This technique is called Discontinuous Transmission (DTX).
• DTX Discontinuous Transmission
• the present invention overcomes the above-identified deficiencies in the art by providing a method and system for multiplexing real time services (e.g., speech communication) and non-priority or less time-critical services (e.g. , short message service and/or electronic mail service) once a silent period is detected in a real time communication. Furthermore, the present invention aborts these other services once the real time communication has become active again after the silent period.
• real time services e.g., speech communication
• non-priority or less time-critical services e.g. , short message service and/or electronic mail service
• a method of allocating communication resources includes the steps of dedicating a communication resource for use by a real time application; monitoring usage of the resource by the real time application; and allocating the resource for use by a non- priority application when the resource is not being used by the real time application.
• a system for allocating communication resources includes a device that monitors an activity status of a first application and transmits a status signal, and a switch coupled to a transmitter and responsive to the status signal.
• the switch couples the first application to the transmitter if the status signal indicates that the first application is active, and the switch couples the second application to the transmitter if the status signal indicates that the first application is not active.
• a system for allocating communication resources includes a first module dedicating a communication resource for use by a real time application; a second module monitoring usage of the resource by the real time application; and a third module allocating the resource for use by a non-priority application when the resource is not being used by the real time application.
• FIG. 1 illustrates a protocol architecture for communicating across an air link
• FIG. 2 illustrates an exemplary embodiment of the present invention
• FIG. 3 A is a flow chart illustrating an exemplary scheduling technique for the downlink of the present invention
• FIG. 3B is a flow chart illustrating an exemplary scheduling technique for the uplink of the present invention.
• FIG. 4 illustrates an allocation of blocks in an exemplary embodiment of the present invention.
• FIG. 2 illustrates an exemplary embodiment of the present invention.
• a communication system 200 includes a base station 202 and a plurality of communication devices 204, 206.
• Communication device 206 includes a transceiver 211, a speech codec 213, and a module 207 that performs VAD, SID, and DTX functions.
• Communication device 204 includes a transceiver 205 and a non-priority (NP) application 215 (e.g., short message service or electronic mail service).
• NP non-priority
• device 206 is an RT device and device 204 is an NP device.
• the base station 202 includes a transceiver 214 which is connected to a multiplexing device 212.
• the multiplexing device 212 selectively connects a speech codec 208, or other real time (RT) application, and an NP application 210 to the transceiver 214. Though only one NP application is shown in FIG. 2, multiple NP applications can be provided and selectively connected to multiplexing device 212 for selective access to transmit or receive resources in the base station.
• the speech codec 208 includes a module 209 that performs VAD, SID, and DTX functions.
• the multiplexing device 212 connects the speech codec to the transceiver 214.
• the multiplexing device 212 connects the NP application 210 to the transceiver 214.
• the multiplexing device 212 allows NP applications to access the same transmission resource (e.g., blocks) used by the real time (RT) application(s). Since at least some resources are typically reserved for the RT application(s) when an RT application is operating, the present invention increases overall system capacity by making it possible for an NP application to "steal" back the reserved RT resource during times when there is no speech activity.
• FIG. 3A is a flow chart illustrating an exemplary scheduling technique for the downlink (DL) of the present invention.
• DL downlink
• the silent speech blocks are not being transmitted to the RT device 206, comfort noise can be generated at the RT device 206 during the periods when the allocated transmission resource is being used by NP applications.
• further DL blocks containing a SID may be transmitted periodically (e.g., every 480 milliseconds (ms)) so that the parameters used to generate the comfort noise can be updated.
• the VAD in the speech codec 208 examines each RT speech block produced by the RT application. If, in step 320, the VAD detects speech in the speech block, the DL block is scheduled for the RT application in step 322 and the multiplexing device 212 connects the speech codec 208 to the transceiver. If the VAD detects a silent speech block, a first DL block containing a SID is transmitted to the RT device 206. In step 323, the SID is used to create (or update) the parameters used to generate comfort noise. In step 324, the next DL block is scheduled for the NP application and the multiplexing device 212 connects the NP application 210 to the transceiver 214.
• the RT device 206 detects a silent period for the next UL block, the RT device 206 sends a first UL block containing a SID which informs the communication system that the RT device 206 is entering a silent period.
• further UL blocks containing a SID may be transmitted periodically (e.g., every 480 milliseconds (ms)) so that the parameters used to generate the comfort noise can be updated.
• an NP application(s) can be allocated UL resources (e.g.
• the RT application from the RT device 206 will still be allocated a resource periodically so that the communication system can determine when the RT application wishes to resume sending UL blocks.
• the RT application may experience a loss of data or delay in reacquiring its UL resource after the period of inactivity ends.
• the frequency of UL block allocation to the NP application(s) should be set to a value that provides the desired tradeoff (loss and/or delay) of UL blocks for the RT application and additional throughput for the NP application(s).
• the communication system receives an UL block from a RT device 206.
• the communication system determines if the UL block from the communication device 206 includes a SID. If speech is detected instead of a SID, then the next UL block is scheduled for the RT user in step 336. If, however, a SID is detected, then in step 334 in this example, the next three UL blocks are scheduled as follows: (1) the first UL block is scheduled for the NP application; (2) the second UL block is scheduled for the RT application; and (3) the third UL block is scheduled for the NP application.
• the RT application can be quickly resumed if it has speech blocks to transmit.
• the specific interleaving pattern can be varied based on the desired effect on the QoS of the system. For example, at a periodicity of N blocks, one block is scheduled for RT and N - 1 blocks are scheduled for ⁇ P. If the spacing of the scheduled UL RT blocks is kept small (e.g. , within two blocks or 20 ms), then the RT application should not suffer a noticeable loss of speech. However, other RT applications may have a higher tolerance to the loss of blocks prior to resuming communications, which allows for greater spacing between the scheduled UL RT blocks (e.g., three blocks or more).
• step 338 during the scheduled UL RT block, the communication system checks to see if an UL RT block has been sent. If an UL RT block has been sent, the communication system checks to see if the block contains speech or a SID. If it contains speech, then the next unscheduled UL block is scheduled for the RT application in step 336. If, in step 340, the UL RT block contains a SID, the comfort noise parameters are updated at the communication system and the next three UL blocks are scheduled according to step 334. If no UL RT block was sent to the communication system, the next three UL blocks are also scheduled according to step 334.
• FIG. 4 illustrates an allocation of blocks in the exemplary embodiment of the present invention as described above with respect to FIG. 3B.
• the DL frame from the communication system, the UL frame from a communication device using an RT application, and the UL frame from a communication device using an NP application are shown.
• Each block in the DL frame includes a Uplink State Flag field (USF) 352, 360 and a Temporary Flow Identifier field (TFI) 354.
• USF field informs the communication devices of the allocation for the next UL block.
• a DL block 350 includes a USF which has the value RT (see USF 352)
• the communication device running the RT application is alerted that it has been scheduled to transmit an RT block 362 on the next available UL opportunity.
• the USF has a value of NP (see DL block 358, USF 360)
• the communication device using the NP application is alerted that is has been scheduled to transmit an NP block 374 on the next available UL opportunity.
• the TFI 354 is used to indicate an intended recipient of the payload 356 (e.g., speech data) of the DL block 350, 358.
• the UL blocks also include a TFI field which indicate the identity of the sender (e.g., TFI 364 for RT applications and TFI 376 for NP applications).
• UL RT block 370 includes a SID 368 message indicating the beginning of a silent period.
• Blocks 372 and 380 represent unused blocks by the RT communication device during a scheduled time. The communication system is alerted to the resumption of RT communication by the RT communication device by receiving block 382 in its scheduled timeslot. Normal RT communication is then resumed after the last scheduled UL NP block 375 with UL RT block 384.
• the un-sent blocks can be stored in the communication device and transmitted at the next scheduled opportunity. This technique will introduce a delay proportional to the number of un-sent blocks stored in the communication device.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)
• Telephonic Communication Services (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

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• 2000
  • 2000-06-30 AU AU61920/00A patent/AU6192000A/en not_active Abandoned
  • 2000-06-30 CN CNB008107904A patent/CN1137599C/zh not_active Expired - Fee Related
  • 2000-06-30 WO PCT/SE2000/001399 patent/WO2001008426A2/en active Search and Examination
  • 2000-06-30 EP EP00948439A patent/EP1197115A2/de not_active Withdrawn
  • 2000-06-30 CA CA002378619A patent/CA2378619A1/en not_active Abandoned
  • 2000-07-19 AR ARP000103723A patent/AR031523A1/es not_active Application Discontinuation

Non-Patent Citations (1)

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