METHOD OF AND APPARATUS FOR PHYSICAL RANDOM ACCESS IN COMMUNICATION NETWORK
In an embodiment of the invention, there is proposed a method of and apparatus for accessing in a user equipment, the method including the steps of: i) performing a random access on a predetermined resource according to a channel condition of the user equipment, wherein the predetermined resource is associated with the channel condition of the user equipment; and ii) receiving, on a PDCCH, a response to the random access from an eNB. With this solution, during a random access of a user equipment, particularly a MTC device, an eNB can perform a Random Access Response (RAR) adaptively using a different number of Control Channel Elements (CCEs) according to an indication, capable of reflecting a channel condition, e.g., a signal to noise ratio, of the user equipment, thereby saving the channel resource.
1 . A method of accessing, in a user equipment, the method comprising:
performing a random access on a predetermined resource according to a channel condition of the user equipment, wherein the predetermined resource is associated with the channel condition of the user equipment; and
receiving, on a PDCCH, a response to the random access from an eNB.
2 . The method according to claim 1 , wherein if an error occurs with decoding the PDCCH in receiving the response, then after receiving the response, the method further comprises:
performing a random access on a second predetermined resource, wherein a channel condition associated with the second predetermined resource is poorer than the channel condition of the user equipment.
3 . The method according to claim 1 , wherein the predetermined resource is time resource or frequency resource of a random access occasion.
4 . The method according to claim 1 , wherein before performing the random access, the method further comprises:
allocating the random access to a first set of timeslots according to a predetermined probability; and
performing the random access further comprises:
performing the random access on the predetermined resource belonging to the first set of timeslots.
5 . The method according to claim 4 , wherein the predetermined probability is derived via a modulo operation of an international mobile subscriber identity code of the user equipment modulo 2 N , wherein N is a positive integer.
6 . The method according to claim 1 , wherein before the step of performing the random access, the method further comprises:
receiving a first broadcast message, from the eNB, indicating an association between the channel condition and the predetermined resource.
7 . The method according to claim 3 , wherein the time resource is a configuration index, the channel condition is a signal to noise ratio; and performing the random access further comprises:
performing the random access on a first configuration index associated with a first interval of values, if the signal to noise ratio lies in the first interval of values.
8 . A method, in an eNB, of responding to an access of a user equipment, the method comprising:
determining a predetermined resource used by the user equipment according to a random access of the user equipment; and
responding to the random access of the user equipment in a PDCCH format associated with the predetermined resource.
9 . The method according to claim 8 , wherein the predetermined resource is time resource or frequency resource of a random access occasion.
10 . The method according to claim 8 , wherein responding to the random access further comprises:
determining the associated PDCCH format according to a location of the predetermined resource in a first set of timeslots where the predetermined resource is located.
11 . The method according to claim 8 , wherein before determining the predetermined resource, the method further comprises:
transmitting to the user equipment a first broadcast message indicating an association between a channel condition of the user equipment and the predetermined resource.
12 . The method according to claim 9 , wherein the time resource is a configuration index, and responding to the random access further comprises:
responding to the random access of the user equipment in a PDCCH format associated with a first configuration index, if the user equipment performs the access on the predetermined first configuration index.
13 . An apparatus for accessing, in a user equipment, the apparatus comprising:
a random access device for performing a random access on a predetermined resource according to a channel condition of the user equipment, wherein the predetermined resource is associated with the channel condition of the user equipment; and
a response receiving device for receiving, on a PDCCH, a response to the random access from an eNB.
14 . The apparatus according to claim 13 , wherein the channel condition is a signal to noise ratio.
15 . An apparatus, in an eNB, for responding to an access of a user equipment, the apparatus comprising:
a resource determining device for determining a predetermined resource used by the user equipment according to a random access of the user equipment; and
an access responding device for responding to the random access of the user equipment in a PDCCH format associated with the predetermined resource.
16 . The apparatus according to claim 15 , further comprising:
a broadcast message transmitting device for transmitting to the user equipment a first broadcast message indicating an association between a channel condition of the user equipment and the predetermined resource.