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WO2011041926A1 - Signalisation de bits d'indication d'une charge de canal à accès aléatoire - Google Patents

Signalisation de bits d'indication d'une charge de canal à accès aléatoire Download PDF

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Publication number
WO2011041926A1
WO2011041926A1 PCT/CN2009/074362 CN2009074362W WO2011041926A1 WO 2011041926 A1 WO2011041926 A1 WO 2011041926A1 CN 2009074362 W CN2009074362 W CN 2009074362W WO 2011041926 A1 WO2011041926 A1 WO 2011041926A1
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WIPO (PCT)
Prior art keywords
load
random access
component carriers
rach
indications
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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PCT/CN2009/074362
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English (en)
Inventor
Jian Feng Qiang
Peter Skov
Juha S. Korhonen
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Nokia Inc
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Nokia Inc
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Priority to PCT/CN2009/074362 priority Critical patent/WO2011041926A1/fr
Publication of WO2011041926A1 publication Critical patent/WO2011041926A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/002—Transmission of channel access control information
    • H04W74/006—Transmission of channel access control information in the downlink, i.e. towards the terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H04W74/0838—Random access procedures, e.g. with 4-step access using contention-free random access [CFRA]

Definitions

  • the exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs and, more specifically, relate to control and management of random access channels between a network access node, such as an eNB, and a user device or user equipment (UE).
  • a network access node such as an eNB
  • UE user equipment
  • eNB EUTRAN Node B (evolved Node B)
  • EUTRAN evolved UTRAN
  • UTRAN-LTE UTRAN-LTE
  • EUTRA evolved UTRAN
  • OFDMA OFDMA
  • SC-FDMA SC-FDMA
  • This system may be referred to for convenience as LTE Rel-8, or simply as Rel-8.
  • the set of specifications given generally as 3GPP TS 36.xyz (e.g., 36.211, 36.311, 36.312, etc.) may be seen as describing the Release 8 LTE system.
  • FIG 1 reproduces Figure 4.1 of 3GPP TS 36.300, and shows the overall architecture of the E-UTRAN system.
  • the E-UTRAN system includes eNBs, providing the EUTRA user plane (PDCP/RLC/M AC/PHY) and control plane (RRC) protocol terminations towards the UE.
  • the eNBs are interconnected with each other by means of an X2 interface.
  • the eNBs are also connected by means of an SI interface to an EPC, more specifically to a MME (Mobility Management Entity) by means of a SI MME interface and to a Serving Gateway (SGW) by means of a SI interface.
  • the SI interface supports a many to many relationship between MMEs / Serving Gateways and eNBs.
  • the eNB hosts the following functions:
  • Radio Resource Management Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both uplink and downlink (scheduling);
  • IP header compression and encryption of the user data stream
  • LTE-A LTE-Advanced
  • LTE-A A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost.
  • the RACH procedure plays an important role in RRC connection setup, RRC connection wakeup after a long DRX period, and in a handover procedure.
  • the RACH is characterized by a limited amount of control information a risk of collision. Normal DL/UL transmission can take place after the RACH procedure(s) are completed.
  • the RACH procedure is performed for the following five events in the LTE system: 1. Initial access from RRCJDLE;
  • the random access procedure takes two distinct forms:
  • the random access procedure can become a bottleneck in a reduced RRC states scenario (there are only two RRC states: RRC-idle and RRC-connected) in the LTE Rel-8 system.
  • the RACH is the only mechanism to transition from the RRC-idle to the RRC-connected states (of reactive UEs).
  • the RACH load from initial access and RRC connection re-establishment is large.
  • the response time of the RACH procedure in LTE is more stringent than previous systems, such as UMTS, as the end-to-end delay requirement is more stringent than that of UMTS.
  • the number of users can exceed 200,000 in a 500m cell (e.g., see R2-062923, "C-RNTI length in LTE", NTT DoCoMo). By a fairly modest estimation as many as 7,000 UEs may be camping in the 10MHz system (e.g., see R2-070205, "LTE cell load / RACH load estimations", Samsung).
  • the asynchronous RACH (aRACH) load is handled with random preambles, and a large load is handled with dedicated preambles.
  • Figure 3 shows both the aRACH load and the dedicated preamble load for "normal (RACH load)", “possible (RACH load)” and “rare (rarely high load)” situations, and reproduces Figure 2 of R2-070205.
  • the total number of PRACH preamble sequences is a maximum of 64 per cell in the LTE system.
  • the desired preamble collision probability could typically be around 1%, meaning that the average RACH load should be less than one random signature per a set of 64 signatures.
  • the available PRACH preamble resources will be critical when compared with the possible RACH load in a LTE cell.
  • LTE-A should operate in spectrum allocations of different sizes, including wider spectrum allocations than those of Rel-8 LTE, e.g., up to 100MHz, to achieve the peak data rate of lOOMbit/s for high mobility and 1 Gbit/s for low mobility. It has been agreed that carrier aggregation is considered for LTE-A in order to support bandwidths larger than 20 MHz.
  • carrier aggregation where two or more component carriers (CC) are aggregated, is considered for LTE- Advanced in order to support transmission bandwidths larger than 20DMHz.
  • the carrier aggregation could be contiguous or non-contiguous.
  • a terminal may simultaneously receive one or multiple component carriers depending on its capabilities.
  • An LTE-Advanced terminal with reception capability beyond 20 MHz can simultaneously receive transmissions on multiple component carriers.
  • An LTE Rel-8 terminal can receive transmissions on a single component carrier only, provided that the structure of the component carrier follows the Rel-8 specifications.
  • Rel-8 terminals receive/transmit on one component carrier, whereas LTE-Advanced terminals may receive/transmit on multiple component carriers simultaneously to achieve higher bandwidths.
  • LTE-A should be backwards compatible with Rel-8 LTE in the sense that a Rel-8 LTE terminal should be operable in the LTE-A system, and that a LTE-A terminal should be operable in a Rel-8 LTE system.
  • the transition time (excluding downlink paging delay and NAS signaling delay) is of less than 100 ms from a camped-state, such as Release 6 Idle Mode, to an active state, such as Release 6 CELL_DCH, in such a way that the user plane is established.
  • the transition time (excluding DRX interval) is less than 50 ms between a dormant state, such as Release 6 CELL_PCH, and an active state, such as Release 6 CELL_DCH.
  • a large number of users per cell can have quasi-instantaneous access to radio resources in the active state. At least 200 users per cell should be supported in the active state for spectrum allocations up to 5 MHz, and at least 400 users for higher spectrum. A much higher number of users are expected to be supported in the dormant and camped state.
  • Figure 5 shows the LTE C-plane latency requirement, as per 3GPP TR 25.913 V8.0.0, (2008-12) Technical Report 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN) (Release 8).
  • E-UTRA Evolved UTRA
  • E-UTRAN Evolved UTRAN
  • Figure 6 reproduces Figure 7.1 of 3GPP TR 36.913 V8.0.1, and shows the LTE-A C-plane latency requirement.
  • the LTE-A C-plane latency requirement is significantly decreased as compared to LTE Rel-8.
  • the C-Plane latency takes into account RAN and CN latencies (excluding the transfer latency on the SI interface) in unloaded conditions.
  • the transition time from Idle mode (with IP address allocated) to the Connected mode is less than 50 ms, including the establishment of the user plane (excluding the SI transfer delay).
  • the transition time from a "dormant state" in Connected Mode i.e., DRX substate in Connected Mode in E-UTRAN
  • 10 ms excluding the DRX delay
  • LTE-A capacity requirement there should be support for at least 300 active users without DRX in a 5 MHz bandwidth, while the same number of RRC connections with DRX as in Rel-8 E-UTRA and E-UTRAN (16,000) is expected.
  • the control plane latency in LTE-A is even more aggressive than LTE, as in LTE there are 100ms from the RRC_idle state to the RRC_connected state, and 50ms from "out of sync" to "in sync” in RRC_connected state, while in LTE-A there are 50ms from the RRC_idle state to the RRC_connected state, and only 10ms from the "out of sync" to "in sync” in RRC_connected state. Because of the more stringent latency requirement of LTE-A, fewer preamble collisions are allowed and more RACH resources (per UE) are needed than in LTE Rel-8.
  • the eNB estimates the RACH load and selects these parameters accordingly and broadcasts them to the UEs.
  • a radio protocol is very efficient if the signaling procedure is straight forward.
  • the RACH procedure represents a major challenge to the C-plane latency of LTE-A due at least to the inherent risk of collision (and subsequent backoff and the iteration of contention between multiple UEs).
  • the exemplary embodiments of this invention provide a method that comprises receiving a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers; selecting a random access channel based at least in part on the received load indications; and transmitting on the selected random access channel.
  • the exemplary embodiments of this invention provide an apparatus that comprises a processor and a memory including computer program code.
  • the memory and computer program code are configured to, with the processor, cause the apparatus at least to perform, receiving a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers; selecting a random access channel based at least in part on the received load indications; and transmitting on the selected random access channel.
  • the exemplary embodiments of this invention provide a method that comprises determining a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers; transmitting the determined load indications into a cell; and receiving transmissions from a plurality of user equipment on certain random access channels that are selected by individual ones of the user equipment in accordance with the transmitted load indications.
  • Figure 1 reproduces Figure 4.1 of 3GPP TS 36.300, and shows the overall architecture of the EUTRAN system.
  • Figure 2 shows a simplified block diagram of various electronic devices that are suitable for use in practicing the exemplary embodiments of this invention.
  • FIG 3 illustrates estimated RACH load of Random/Dedicated Signatures, and reproduces Figure 2 of R2-070205.
  • Figure 4 shows an example of carrier aggregation for the LTE-A system.
  • Figure 5 shows a LTE C- lane latency requirement, and reproduces Figure 6.1 of 3GPP TR 25.913 V8.0.0.
  • Figure 6 reproduces Figure 7.1 of 3GPP TR 36.913 V8.0.1, and shows the LTE-A C-plane latency requirement.
  • FIGS 7 and 8 are each a logic flow diagram illustrating the operation of a method, and a result of execution of computer program instructions embodied on a computer readable medium, in accordance with the exemplary embodiments of this invention.
  • the terminal In previous cellular systems, such as HSPA and LTE Rel-8, the terminal has only one carrier present. As such, the issue of RACH load balancing amongst different component carriers does not exist. Any existing carrier load balancing is based on carrier reselection, wherein the terminal selects the RACH/preamble without a priori knowledge of the RACH load per CC.
  • An aspect of the exemplary embodiments of this invention is to provide flexible RACH load balancing by the use of RACH load indicator bits on a BCH in a multiple CC wireless communication system.
  • a wireless network 1 is adapted for communication over a wireless link 11 with an apparatus, such as a mobile communication device which may be referred to as a mobile station, which may be a UE 10, via a network access node, such as a Node B (base station), and more specifically an eNB 12.
  • a mobile communication device which may be referred to as a mobile station, which may be a UE 10
  • a network access node such as a Node B (base station)
  • eNB 12 evolved Node B
  • the network 1 may include a network control element (NCE) 14 that may include the MME/SGW functionality shown in Figure 1, and which provides connectivity with a further network, such as a telephone network and/or a data communications network (e.g., the internet).
  • the UE 10 includes a controller, such as a computer or a data processor (DP) 10A, a computer-readable memory medium embodied as a memory (MEM) 10B that stores a program of computer instructions (PROG) IOC, and a suitable radio frequency (RF) transceiver 10D for bidirectional wireless communications with the eNB 12 via one or more antennas.
  • DP data processor
  • PROG program of computer instructions
  • RF radio frequency
  • the eNB 12 also includes a controller, such as a computer or a data processor (DP) 12A, a computer-readable memory medium embodied as a memory (MEM) 12B that stores a program of computer instructions (PROG) 12C, and a suitable RF transceiver 12D for communication with the UE 10 via one or more antennas.
  • the eNB 12 is assumed to be associated with at least one cell within which a plurality of the UEs 10 can be present at any given time.
  • the eNB 12 is coupled via a data / control path 13 to the NCE 14.
  • the path 13 may be implemented as the SI interface shown in Figure 1.
  • the eNB 12 may also be coupled to another eNB via data / control path 15, which may be implemented as the X2 interface shown in Figure 1.
  • the UE 10 may be assumed to also include a RACH unit or function 10E, and the eNB 12 also includes a RACH unit or function 12E.
  • the operation of the RACH units/functions 10E, 12E is described in detail below.
  • At least one of the PROGs IOC and 12C is assumed to include program instructions that, when executed by the associated DP, enable the device to operate in accordance with the exemplary embodiments of this invention, as will be discussed below in greater detail. That is, the exemplary embodiments of this invention may be implemented at least in part by computer software executable by the DP 10A of the UE 10 and/or by the DP 12A of the eNB 12, or by hardware, or by a combination of software and hardware (and firmware).
  • the RACH units/functions 10E, 12E may thus also be implemented at least in part by computer software, or by hardware, or by a combination of software and hardware (and firmware).
  • the various embodiments of the UE 10 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.
  • PDAs personal digital assistants
  • portable computers having wireless communication capabilities
  • image capture devices such as digital cameras having wireless communication capabilities
  • gaming devices having wireless communication capabilities
  • music storage and playback appliances having wireless communication capabilities
  • Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.
  • the computer readable MEMs 10B and 12B may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory.
  • the DPs 10A and 12A may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architectures, as non-limiting examples.
  • the overall functionality of the random access procedures between the UE 10 and the eNB 12 have an important bearing on the ability of the system 10 to conform to LTE-A operational requirements.
  • RACH performance in non-contiguous CCs.
  • the path-gain of the radio channel and the RACH power control parameters affect the RACH performance, provided that there is the same RACH load traffic model (hot spot, rural cell, cell radius, or proportion of initial access and RRC connection re-establish), back-off scheme, and so forth applies to the non-contiguous CC case.
  • RACH load traffic model hot spot, rural cell, cell radius, or proportion of initial access and RRC connection re-establish
  • back-off scheme and so forth applies to the non-contiguous CC case.
  • a proper and effective RACH load balance scheme is required for RACH performance optimization under various conditions (e.g., different load traffic, different radio conditions).
  • a further issue to consider is the unequal RACH resources per CC due to different TDD UL/DL slot ratios per CC.
  • a different TDD UL/DL slot ratio per CC is possible when the LTE-A UE 10 has additional RF power amplifiers in the case of non-contiguous carrier aggregation.
  • the RACH resource per CC can be different in this case.
  • the RACH resources and RACH procedures represent a potential impediment in the LTE/LTE-A system.
  • a proper RACH load balancing scheme is needed to deal with at least the following issues:
  • RACH resources are critical as compared to the RACH load in a LTE cell
  • the stringent LTE-A C-plane latency requirement requires that there be a reduced number of RACH collisions and RACH collision-related procedures, such as collision resolution including backoff;
  • a different RACH processing gain is due to a large path gain difference between non-contiguous CCs, wherein the RACH performance is different between CCs, provided the same RACH load, same number of preamble sequences and same RACH power control parameters exist; and.
  • a RACH load indicator scheme and a carrier reselection scheme both have the potential to distribute the RACH load over certain carriers.
  • the former approach efficiently directs the UE 10 to a desired RACH with the use of a priori information.
  • the carrier reselection approach can require more time to perform, due at least to the needed signaling procedure(s) after the UE 10 discovers that it has selected an improper carrier for RACH use.
  • every BCH could carry at least some broadcast information also for the other CCs.
  • every BCH could include information that describes the carrier aggregation configuration (how many carriers there are in total and where they are positioned in frequency), and what the load indicators are for the RACHs on all the carriers. It may also be possible that some DL CCs do not have a BCH, as may be the case in certain asynchronous configurations where there are more DL than UL CCs.
  • the exemplary embodiments of this invention provide a flexible RACH load balancing procedure in a multi-CC scenario.
  • the UE 10 is enabled to access different RACHs on different CCs in, for example, the LTE-A system.
  • the efficient RACH load balancing in the multiple-CC scenario is important to ensure good RACH performance according to different resource conditions.
  • These exemplary embodiments can beneficially be used when there are Rel-8/9/10 UEs 10 coexisting in the LTE-A system, and thus are backwards compatible with UE releases that predate LTE-A .
  • the exemplary embodiments of this invention make use of RACH load indicator bits that are signaled (broadcast) into the cell by the eNB 12. These RACH load indicator bits instruct and/or aid the UE 10 in selecting RACHs in different CCs flexibly according to the system RACH load situation and RACH access policies per CC.
  • the BCH carries information to enable the eNB 12 to influence the RACH load distribution on different CCs. The UE 10 thus is enabled to select more intelligently between RACHs on different CCs by using the BCH information.
  • the operation of the exemplary embodiments may be as follows. 1.) The eNB 12 measures the RACH load per CC, and determines a set of "RACH load indicator bits" according to a carrier access policy.
  • the RACH load may include random access requests from Rel-8/9/10 UEs, and thus the technique is adaptive to and supports Rel-8/9/10 UE 10 coexistence, lb.
  • a Rel-10 eNB 12 can distinguish the RACH load from Rel-8/9/10 UEs, and may derive different RACH load indicator bits according to different policies as described in further detail below.
  • the eNB 12 broadcasts information, which may be referred to for convenience as "RACH load indicator bits per CC", in the LTE-A cell, thereby informing the UEs 10 within the cell of the opportunities to access RACHs on different CCs.
  • the Rel-10 (LTE-A) UE 10 accesses the RACH on the desired CC according to the received RACH load indicator bits information.
  • the RACH load indicator bits per CC may be derived by the RACH function 12E of the eNB 12 in different scenarios by use of the following exemplary policies.
  • Equal RACH load balance per CC In this case a Rel-10 (LTE-A compatible) UE 10 selects a proper RACH on a certain CC to ensure equal load balancing. In some cases Rel-8/9/10 UEs 10 may initiate RACH procedure on the same set of CCs. However, the RACH load on certain CCs can become unbalanced due to Rel-8/9 UEs that are camping.
  • the RACH load of the LTE-A UEs 10 is preferably balanced to ensure good RACH performance. Equal RACH load balance of a purely LTE-A UE 10 can be achieved by this technique as well.
  • Non-contiguous CC or different radio channel conditions In this case the RACH demodulation performance can be very different due to different path gains in different CCs. In this case the RACH load indicator bits are adaptive to each CC.
  • C. Heterogeneous deployment, different priority of autonomous carrier selection in SON, relay cells and home eNB cells: In this case different CC/cells may have a different access priority class. A flexible scheme is needed to accommodate this situation. For example, radio channel conditions, the UE 10 power class and the power control parameters of the RACH impact the RACH optimization in a SON.
  • D. Different UL/DL slot ratios per CC in TDD carrier aggregation: In this case the eNB 12 determines or derives/composes the RACH load indicator bits per CC to accommodate different RACH resources on different CCs with different UL/DL slot ratios.
  • Capacity optimization/QoS differentiation in (non-) contiguous CCs For example, flexibility of load balancing per CC is desired by the eNB 12 according to capacity optimization/QoS differentiation.
  • the QoS of an emergency call, high vehicle speed call, or a poor path-gain call can be met in lightly loaded CC.
  • carrier selection in the RRC_idle state in LTE/LTE-A is possible with the use of these exemplary embodiments.
  • the RACH load indicator bits may be derived/composed by the eNB RACH function 12E.
  • the RACH load indicator bits are provided as limited ranks, such as “unhappy”, “ok”, “happy”, etc., where “happy” indicates a light RACH load on a particular CC, while “unhappy” indicates a heavy load on the CC.
  • the RACH load indicator bits are provided as a relative selection probability P ; for the i-th carrier.
  • the RACH function 10E of the UE 10 selects the i-th
  • each BCH contains carrier aggregation information including load indicators for all RACHs.
  • Both signaling schemes can be applied in symmetric carrier aggregations where each DL CC contains a BCH and corresponds to one UL CC. Both schemes are applicable also with those asymmetric carrier aggregations where there are more DL than UL CCs.
  • a BCH may be common for two or more UL CCs and may necessarily carry load indicators for more than one RACH.
  • the use of these exemplary embodiments provides improved efficiency, as the use of the RACH load indicator bits is more efficient than the use of the conventional, legacy carrier reselection scheme in informing the RACH decision making functionality 10E of the UE 10.
  • carrier reselection requires a more involved signaling procedure once the UE 10 discovers that it has selected an improper carrier.
  • the use of these exemplary embodiments is compatible with existing RACH procedures, as they are operable with current (fast) control parameters (back-off time, etc.), schemes of the Rel-8 RACH.
  • the flexible RACH load balance approach may be considered as typically a slow procedure.
  • the update interval may be some multiple of the typical BCH information update interval, such as 80ms in Rel-8.
  • the use of these exemplary embodiments is adaptive to Rel-8/9/10 UE 10 coexistence, as this flexible RACH load balance approach is transparent to Rel-8/9 UEs, while the Rel-10 (LTE-A) UE 10 RACH selection scheme efficiently selects the proper RACH on a certain CC according to the Rel-8/Rel-9 UE 10 RACH load per CC, as well as other policies of interest.
  • the use of these exemplary embodiments provides a RACH load balancing scheme in the multi-CC scenario in the LTE/LTE-A system.
  • the eNB 12 is enabled to control, or at least influence, the UE 10 RACH selection, thereby giving the eNB 12 flexibility for achieving a desired load balancing, e.g., whether to establish a balanced RACH load or an imbalanced RACH load across CCs.
  • a desired load balancing e.g., whether to establish a balanced RACH load or an imbalanced RACH load across CCs.
  • the use of these exemplary embodiments provides advantages over conventional techniques of selecting the channels at the network side since, specifically for random access channels, this requires the UEs to be constantly reconfigured in accordance with the load, as the load continuously shifts as a result of at least DTX behavior.
  • the basic nature of RACH operation is such that the timing of RACH transmissions are unpredictable (i.e., random).
  • the RACH indicator bits may be a 5-bit field, where the state of each bit would indicate the suitability/non-suitability of the associated CC, assuming at least that every BCH (on different CCs) would contain information on the entire aggregation configuration.
  • FIG. 7 is a logic flow diagram that illustrates the operation of a method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention.
  • a method performs, at Block 7A, a step of receiving a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers.
  • Block 7B there is a step of selecting a random access channel based at least in part on the received load indications.
  • Block 7C there is a step of transmitting on the selected random access channel.
  • the load indications comprise a set of bits each having one of two states for indicating a current load of an associated component carrier.
  • the load indications each indicate a relative selection probability of an associated component carrier.
  • one broadcast channel contains load indications for random access channels on a plurality of component carriers.
  • the received load indications are indicative of a network access node desired loading of individual ones of the component carriers.
  • the method is performed as a result of the execution of computer program code by a data processor, where the computer program code is stored in a memory, and where the data processor and the memory comprise part of a user equipment.
  • FIG. 8 is a logic flow diagram that illustrates the operation of a further method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention.
  • a method performs, at Block 8 A, a step of determining a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers.
  • At Block 8B there is a step of transmitting the determined load indications into a cell.
  • Block 8C there is a step of receiving transmissions from a plurality of user equipment on certain random access channels that are selected by individual ones of the user equipment in accordance with the transmitted load indications.
  • the load indications comprise a set of bits each having one of two states for indicating a current load of an associated component carrier.
  • the load indications each indicate a relative selection probability of an associated component carrier.
  • the load indication for each of the plurality of component carriers are transmitted on a downlink broadcast channel, where in one case there is a one-to-one correspondence between downlink broadcast channels and uplink random access channel carriers, and in another case there not a one-to-one correspondence between downlink broadcast channels and uplink random access channel carriers, and further comprising transmitting additional information to indicate which uplink carriers the transmitted load indications refer to.
  • the load indications are determined based on a network access node desired loading of individual ones of the component carriers, where the component carriers are one of contiguous component carriers or non-contiguous component carriers.
  • load indications are determined to accommodate different random access channel resources on different component carriers having different uplink/downlink slot ratios.
  • the blocks shown in Figures 7 and 8 may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function(s).
  • the exemplary embodiments of this invention further provide an apparatus comprising means for receiving a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers; means for selecting a random access channel based at least in part on the received load indications; and means for transmitting on the selected random access channel.
  • the exemplary embodiments of this invention further provide an apparatus comprising means for determining a load indication for each of a plurality of component carriers, where an individual one of a plurality of random access channels are associated with an individual one of said plurality of component carriers; means for transmitting the determined load indications into a cell; and means for receiving transmissions from a plurality of user equipment on certain random access channels that are selected by individual ones of the user equipment in accordance with the transmitted load indications.
  • the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof.
  • some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto.
  • firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto.
  • While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
  • the integrated circuit, or circuits may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this invention.
  • connection means any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together.
  • the coupling or connection between the elements can be physical, logical, or a combination thereof.
  • two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.
  • electromagnetic energy such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region
  • RACH load indicator bits are not intended to be limiting in any respect, as these parameters may be identified by any suitable names. Further, the various names assigned to different channels (e.g., BCH, RACH, etc.) are not intended to be limiting in any respect, as these various channels may be identified by any suitable names.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Un procédé comprend une étape consistant à recevoir une indication de charge pour chacune d'une pluralité de porteuses composantes, où l'un individuel d'une pluralité de canaux à accès aléatoire est associé à l'une individuelle de la pluralité de porteuses composantes. Le procédé comprend en outre une étape consistant à sélectionner un canal à accès aléatoire sur la base, au moins en partie, des indications de charge reçues et à transmettre sur le canal à accès aléatoire sélectionné.
PCT/CN2009/074362 2009-10-08 2009-10-08 Signalisation de bits d'indication d'une charge de canal à accès aléatoire Ceased WO2011041926A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2009/074362 WO2011041926A1 (fr) 2009-10-08 2009-10-08 Signalisation de bits d'indication d'une charge de canal à accès aléatoire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2009/074362 WO2011041926A1 (fr) 2009-10-08 2009-10-08 Signalisation de bits d'indication d'une charge de canal à accès aléatoire

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WO2011041926A1 true WO2011041926A1 (fr) 2011-04-14

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WO (1) WO2011041926A1 (fr)

Cited By (5)

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Publication number Priority date Publication date Assignee Title
WO2014099474A1 (fr) * 2012-12-18 2014-06-26 Qualcomm Incorporated Sélection de cellules wan-wlan dans des ue
US9462447B2 (en) 2014-10-31 2016-10-04 Motorola Solutions, Inc. Methods and systems for allocating resources from component carriers to a public-safety mobile radio
WO2018030953A1 (fr) * 2016-08-12 2018-02-15 Telefonaktiebolaget Lm Ericsson (Publ) Distribution de charge pour accès aléatoire
EP3503662A4 (fr) * 2016-09-09 2019-07-10 Huawei Technologies Co., Ltd. Procédé de communication, équipement d'utilisateur, et dispositif de réseau associé
CN115801212A (zh) * 2022-11-17 2023-03-14 北京物资学院 应用于载波聚合的上行下行时隙配比指示方法和装置

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WO2006110916A1 (fr) * 2005-04-13 2006-10-19 Intel Corporation Procedes et appareil pour selectionner les canaux de communication sur la base des informations de charge des canaux
CN101534235A (zh) * 2008-03-12 2009-09-16 华为技术有限公司 一种多载波接入的方法、系统及设备

Patent Citations (2)

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Publication number Priority date Publication date Assignee Title
WO2006110916A1 (fr) * 2005-04-13 2006-10-19 Intel Corporation Procedes et appareil pour selectionner les canaux de communication sur la base des informations de charge des canaux
CN101534235A (zh) * 2008-03-12 2009-09-16 华为技术有限公司 一种多载波接入的方法、系统及设备

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014099474A1 (fr) * 2012-12-18 2014-06-26 Qualcomm Incorporated Sélection de cellules wan-wlan dans des ue
US9374774B2 (en) 2012-12-18 2016-06-21 Qualcomm Incorporated WAN-WLAN cell selection in UEs
US9462447B2 (en) 2014-10-31 2016-10-04 Motorola Solutions, Inc. Methods and systems for allocating resources from component carriers to a public-safety mobile radio
WO2018030953A1 (fr) * 2016-08-12 2018-02-15 Telefonaktiebolaget Lm Ericsson (Publ) Distribution de charge pour accès aléatoire
RU2718416C1 (ru) * 2016-08-12 2020-04-02 Телефонактиеболагет Лм Эрикссон (Пабл) Распределение нагрузки для произвольного доступа
EP3503662A4 (fr) * 2016-09-09 2019-07-10 Huawei Technologies Co., Ltd. Procédé de communication, équipement d'utilisateur, et dispositif de réseau associé
US10939410B2 (en) 2016-09-09 2021-03-02 Huawei Technologies Co., Ltd. Communication method, user equipment, and network device
CN115801212A (zh) * 2022-11-17 2023-03-14 北京物资学院 应用于载波聚合的上行下行时隙配比指示方法和装置

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