COMMUNICATION STATIONS AND METHODS FOR TRANSMITTING ON A RANDOM ACCESS CHANNEL

• US 20110222475A1
• Filed: 03/10/2011
• Published: 09/15/2011
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Borsella, Remo, Hole, David Philip, Venkob, Satish, Faurie, Rene, Kreuzer, Werner Karl, Hanov, Steven Michael
• Granted Patent: US 9,226,254 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Example communication stations and methods for transmitting on a random access channel (RACH) in wireless networks are disclosed herein. An example method for transmitting on an enhanced RACH by a device such that an initial access burst is received in a single time slot by a wireless network involves determining a timing advance, the timing advance being associated with a serving cell. The example method also involves transmitting, using the determined timing advance, the initial access burst, on the enhanced RACH, that includes at least one of an identifier or user data.

Claims

1. A method for transmitting on an enhanced random-access channel (RACH) by a device such that an initial access burst is received in a single time slot by a wireless network, the method comprising:

determining a timing advance, the timing advance being associated with a serving cell; and

transmitting, using the determined timing advance, the initial access burst, on the enhanced RACH, that includes at least one of an identifier or user data.

2. The method of claim 1, wherein the method is performed in a time-division multiple access (TDMA) communication system,

wherein the method further comprises receiving a notification from a base station indicating that the enhanced RACH is configured for initial access transmissions, the notification including parameters defining the enhanced RACH including an identification of time-slots of TDMA frames that comprise the enhanced RACH, and

wherein the user data includes data having a network destination.

3. The method of claim 2 wherein the enhanced RACH is a secondary RACH,

wherein a primary RACH is provided by the base station for transmission of access request messages by devices requesting assignment of a channel resource, and

wherein when the timing advance is unknown, the method further comprises:

using the primary RACH for transmitting access request messages for an assignment of a channel resource for a subsequent transmission of data; and

refraining from transmitting the initial access burst on the enhanced RACH.

4. The method of claim 3 wherein the primary RACH is to be used by the devices without an enhanced-RACH capability for transmitting access request messages,

wherein the enhanced RACH is to be used by the devices having the enhanced-RACH capability when an amount of data for transmission does not exceed an amount that can be transmitted in a single burst for receipt within a single time slot on the enhanced RACH.

5. The method of claim 4 wherein when the amount of data for transmission exceeds an amount that can be transmitted in a single burst for receipt within a single time slot on the enhanced RACH, the method further comprises either:

transmitting the data in multiple initial access bursts on the enhanced RACH based on the timing advance;

or

transmitting an initial access request message on the primary RACH to request an assignment of a channel resource for a subsequent transmission of the data.

6. The method of claim 4 wherein the initial access burst is triggered by an upper-level layer of the device that has data to send to the network destination when the device has no assigned resources on a data channel for data transmission, and

wherein when the amount of data for transmission exceeds a predetermined amount, or when quality-of-service (QoS) requirements for the data do not meet one or more predetermined criteria able to be met by the enhanced RACH, the method comprises:

refraining from transmitting the initial access burst on the enhanced RACH; and

requesting a temporary block flow for transmission of the data.

7. The method of claim 1 wherein the initial access burst transmitted on the enhanced RACH comprises an enhanced access burst in which at least some guard bits are replaced with bits conveying the data, and

wherein the enhanced access burst is configured in accordance with a legacy access burst structure.

8. The method of claim 1 wherein the data transmitted by the device on the enhanced RACH comprises data having either a low-latency requirement or a quality of service level requirement that does not require an acknowledgement from a radio access network.

9. The method of claim 1 wherein transmissions on the enhanced RACH are to be configured in a normal-burst format,

wherein the method further includes the device configuring the initial access burst for transmission on the enhanced RACH in accordance with a normal-burst format, and

wherein transmission of the initial access burst in the normal-burst format is no greater than a time-slot of the enhanced RACH.

10. The method of claim 9 wherein the device is a non-mobile communication station having a fixed geographic location,

wherein a same timing advance is to be used for the non-mobile communication station for small data transfers over the enhanced RACH, and

wherein the small data transfers comprise machine-type communications (MTC).

11. The method of claim 2 wherein the base station and the device operate within the wireless network,

wherein prior to receiving the notification from the base station of the enhanced RACH, the method comprises the device indicating to the wireless network whether or not the device has enhanced-RACH capability to support small data transmission on the enhanced RACH and provides the wireless network with a full-length identifier that uniquely identifies the device,

wherein the notification received from the base station includes the identifier to identify the device from other devices with enhanced-RACH capability, and

wherein the initial access burst includes the identifier.

12. The method of claim 2 wherein the base station establishes the enhanced RACH by sending an enhanced-RACH notification message on a control channel using a single block packet downlink assignment procedure.

13. The method of claim 1 further comprising transmitting enhanced RACH capability information associated with the device in the initial access burst.

14. A tangible computer readable medium having instructions stored thereon that, when executed, cause a machine to implement the method as defined in claim 1.

15. A device comprising a processor configured to:

configure an initial access burst for transmission on an enhanced random-access channel (RACH) when a timing advance (TA) is known by the communication station, the initial access burst to include at least one of an identifier and user data; and

cause transceiver circuitry to transmit the initial access burst based on the timing advance to be received by a base station within a single time slot of the enhanced RACH.

16. The device of claim 15 wherein the device is configured to operate within a time-division multiple access (TDMA) communication system, and

wherein the transceiver circuitry is further configured to receive a notification from the base station indicating that the enhanced RACH is configured for initial access transmissions, the notification including parameters defining the enhanced RACH including an identification of time-slots of TDMA frames that comprise the enhanced RACH, and

wherein the user data includes data having a network destination.

17. The device of claim 16 wherein the enhanced RACH is a secondary RACH,

wherein a primary RACH is provided by the base station for transmission of access request messages by devices requesting assignment of a channel resource, and

wherein when the timing advance is unknown, the transceiver circuitry is further configured to:

use the primary RACH for transmitting access request messages for an assignment of a channel resource for a subsequent transmission of data; and

refrain from transmitting the initial access burst on the enhanced RACH.