Rach procedures and power level for mtc devices

Abstract

Random access channel (RACH) procedures and power levels for machine type communication (MTC) devices are disclosed. An example method for controlling one or more transmissions between a wireless device and a base station, the one or more transmissions including at least an initial transmission, includes: providing a current timing advance indicative of a propagation delay from the wireless device to the base station; selecting an access timing advance based on the current timing advance; and transmitting the initial transmission using the access timing advance.

1 . A method for controlling one or more transmissions between a wireless device and a base station, the one or more transmissions including at least an initial transmission, the method comprising:
 providing a current timing advance indicative of a propagation delay from the wireless device to the base station;   selecting an access timing advance based on the current timing advance; and   transmitting the initial transmission using the access timing advance.   
     
     
         2 . The method of  claim 1 , wherein selecting the access timing advance comprises selecting the access timing advance from a set of timing advance values ranging from the current timing advance to the current timing advance minus a length of a guard period of the initial transmission. 
     
     
         3 . The method of  claim 2 , wherein the guard period corresponds to a difference between a number of symbols per time slot and a number of payload symbols of the initial transmission. 
     
     
         4 . The method of  claim 1 , wherein transmitting the initial transmission comprises transmitting the initial transmission on a random access channel (RACH), the initial transmission being shorter than a Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN) time slot and the initial transmission comprising a payload, the payload comprising at least one of: tail bits, synchronization sequence bits, or encrypted bits. 
     
     
         5 . The method of  claim 1 , wherein the wireless device is a GERAN mobile station, the base station is a GERAN base station, and the initial transmission is a GERAN access burst. 
     
     
         6 . The method of  claim 1 , wherein selecting the access timing advance comprises selecting the access timing advance using an offset from the current timing advance. 
     
     
         7 . The method of  claim 1 , wherein selecting the access timing advance comprises selecting the access timing advance randomly from a set of access timing advance values. 
     
     
         8 . A wireless device to control one or more transmissions between the wireless device and a base station, the device comprising a logic circuit configured to at least:
 provide a current timing advance indicative of a propagation delay from the wireless device to the base station;   select an access timing advance based on the current timing advance; and   transmit an initial transmission using the access timing advance.   
     
     
         9 . The wireless device of  claim 8 , wherein the logic circuit is configured to select the access timing advance by selecting the access timing advance from a set of timing advance values ranging from the current timing advance to the current timing advance minus a length of a guard period of the initial transmission. 
     
     
         10 . The wireless device of  claim 9 , wherein the guard period corresponds to a difference between a number of symbols per time slot and a number of payload symbols of the initial transmission. 
     
     
         11 . The wireless device of  claim 8 , wherein the logic circuit is configured to transmit the initial transmission by transmitting the initial transmission on a random access channel (RACH), the initial transmission being shorter than a GERAN time slot, and the initial transmission comprising a payload, the payload comprising at least one of: tail bits, synchronization sequence bits, or encrypted bits. 
     
     
         12 . The wireless device of  claim 8 , wherein the logic circuit is configured to select the access timing advance by selecting the access timing advance using an offset from the current timing advance. 
     
     
         13 . The wireless device of  claim 12 , wherein the offset does not exceed a length of a guard period of the initial transmission. 
     
     
         14 . The wireless device of  claim 12 , wherein the logic circuit is configured to select the offset from a hopping sequence of offsets attributed to the wireless device. 
     
     
         15 . A tangible computer readable storage device or storage disk comprising computer readable instructions which, when executed, cause a logic circuit of a wireless device to at least:
 provide a current timing advance indicative of a propagation delay from the wireless device to a base station;   select an access timing advance based on the current timing advance; and   transmit an initial transmission using the access timing advance.   
     
     
         16 . The storage device or storage disk of  claim 15 , wherein the instructions are to cause the logic circuit to select the access timing advance by selecting the access timing advance from a set of timing advance values ranging from the current timing advance to the current timing advance minus a length of a guard period of the initial transmission. 
     
     
         17 . The storage device or storage disk of  claim 16 , wherein the guard period corresponds to a difference between a number of symbols per time slot and a number of payload symbols of the initial transmission. 
     
     
         18 . The storage device or storage disk of  claim 15 , wherein the instructions are to cause the logic circuit to transmit the initial transmission by transmitting the initial transmission on a random access channel (RACH), the initial transmission being shorter than a GERAN time slot, and the initial transmission comprising a payload, the payload comprising at least one of: tail bits, synchronization sequence bits, or encrypted bits. 
     
     
         19 . The storage device or storage disk of  claim 15 , wherein the instructions are to cause the logic circuit to select the access timing advance by selecting the access timing advance using an offset from the current timing advance. 
     
     
         20 . The storage device or storage disk of  claim 19 , wherein the offset does not exceed a length of a guard period of the initial transmission. 
     
     
         21 . The storage device or storage disk of  claim 19 , wherein the instructions are to cause the logic circuit to select the offset from a hopping sequence of offsets attributed to the wireless device.