1. A base station in a carrier aggregating communication network comprising:
a secondary component carrier updating unit configured to update a secondary component earner for a terminal, comprising:
a reconfiguration information transmitting unit configured to transmit to the
terminal "Radio Resource Control" reconfiguration information comprising radio
resource configuration information of an updated secondary component carrier for
configuring the updated secondary component carrier,
wherein mobility control information is not included in the "Radio Resource Control" reconfiguration information, the updated secondary component carrier being configured without reconfiguring of MAC or updating of security key, the secondary component carrier updating unit is further configured to update a secondary component carrier for a terminal by adding a new secondary component carrier or replacing an old secondary component carrier with a new secondary component carrier for the terminal, the component carrier to he used by the terminal is determined at least according to a rule that is decided by a distribution mode in the case that a distribution of coverage range of different available carriers corresponding to the position of the terminal accords with the predetermined distribution mode, wherein the predetermined distribution mode and corresponding rule is one of:
the predetermined distribution mode is that the coverage ranges of different available carriers are substantially the same, and the rule comprises taking each available carrier as a candidate component carrier;
the predetermined distribution mode is that there exists at least one available carrier the coverage range of which is substantially contained within the coverage range of at least one other available carrier, and the rule comprises determining a candidate component carrier at least according to the size of the coverage range of each available carrier; and
the predetermined distribution mode is that there exist at least two available carriers the coverage ranges of which are substantially not coincident with each other nor contained one in the other but overlapped with each other, and the rule comprises determining a candidate component carrier at least according to a position where the terminal is located and a moving direction and moving speed of the terminal.
2. The base station as claimed in claim 1, wherein the new secondary component carrier
is in a deactivated state after being added by the secondary component carrier updating unit.

3. The base station as claimed in claim ], further comprising a status acquisition unit configured to acquire status information of a terminal, a base station and/or a component carrier, wherein the secondary component carrier updating unit is further configured to update the secondary component carrier in case of the status information satisfying a predetermined condition.
4. The base station as claimed in claim 3, wherein the predetermined condition comprises that updating of the secondary component carrier is required for a service or is required for the original base station in consideration of an overall load balance of the network or inter-user interference.
5. The base station as claimed In claim 3, wherein the predetermined condition
comprises that a signal over the old secondary component carrier is degraded in quality.
6. The base station as claimed in claim 3, wherein the predetermined condition comprises that the terminal moves beyond a coverage area of the old secondary component carrier or moves into a coverage area of a new base station.
7. The base station as claimed in claim 3, wherein the predetermined condition comprises that an amount of physical resources over the uplink and downlink of the old secondary component carrier is insufficient.
8. The base station according to any one of claims 1 to 7, wherein the secondary component carrier updating unit further comprises:
an activation command transmission unit configured to transmit an activation command to activate the updated secondary component carrier in the case that the updated
secondary component carrier has not been activated.
9. The base station as claimed in claim 1, wherein the component carrier to be used by
the terminal is further determined according to other factors with different priorities in
determination.
10. A method for updating a secondary component carrier for a terminal in a carrier
aggregating communication network comprising:

transmitting, by a base station hosting an updated secondary component carrier, "Radio Resource Control" reconfiguration information comprising radio resource configuration information of the updated secondary component carrier to the terminal for configuring the updated secondary component carrier.
wherein mobility control information is not included in the "Radio Resource Control" reconfiguration information, the updated secondary component carrier being configured without reconfiguring of MAC or updating of security key, and the method comprises
updating a secondary component carrier further comprising adding a new secondary component carrier or replacing an old secondary component carrier with a new secondary component carrier, and determining the component carrier to be used by the terminal at least according to a rule that is decided by a distribution mode in the case that a distribution of .coverage range of different available carriers corresponding to the position of the terminal accords with the predetermined distribution mode, wherein the predetermined distribution mode and corresponding rule is one of:
the predetermined distribution mode is that the coverage ranges of different available carriers are substantially the same, and die rule comprises taking each available carrier as a candidate component carrier;
the predetermined distribution mode is that there exists at least one available carrier the coverage range of which is substantially contained within the coverage range of at least one other available carrier and the rule comprises determining a candidate component carrier at least according to the size of the coverage range of each available carrier; and
the predetermined distribution mode is that there exist at least two available carriers the coverage ranges of which are substantially not coincident with each other nor contained one in the other but overlapped with each other, and the rule comprises determining a candidate component carrier at least according to a position where the terminal is located and a moving direction and moving speed of the terminal.
11. The method as claimed in claim 10, wherein the new secondary component carrier is in a deactivated state after being added.
12. The method as claimed in claim 10, further comprising acquiring status information of a terminal, a base station and/or a component carrier, wherein the step of adding a new secondary component carrier or replacing an old secondary component carrier with a new

secondary component carrier Is executed In case of the status information satisfying a predetermined condition.
13. The method as claimed in claim 12, wherein the predetermined condition comprises that updating of the secondary component carrier is required for a service or is required for the original base station in consideration of an overall load balance of the network or inter-user interference,
14. The method as claimed in claim 12, wherein the predetermined condition comprises that a signal over the old secondary component carrier is degraded in quality.
15. The method as claimed in claim 12, wherein the predetermined condition comprises that the terminal moves beyond a coverage area of the old secondary component carrier or
moves into a coverage area of a new base station.
16. The method as claimed in claim 12, wherein the predetermined condition comprises
that an amount of physical resources over the uplink and downlink of the old secondary
component carrier is insufficient.
17. The method according to any one of claims 10 to 16, further comprising: transmitting an activation command to activate the new secondary component carrier.
18. A terminal adapted for a carrier aggregating communication network, comprising:
a reconfiguration information receiving unit configured to receive " Radio Resource Control" reconfiguration Information from a base station; and
a radio resource configuring unit configured to configure a new secondary component carrier with radio resource configuration information comprised in the "Radio Resource Control" reconfiguration information,
wherein mobility control information is not included in the "Radio Resource Control" reconfiguration information, the updated secondary component carrier being configured without reconfiguring of MAC or updating of security key, the secondary component carrier updating unit is further configured to update a secondary component carrier for a terminal by adding a new secondary component carrier or replacing an old secondary component carrier with a new secondary component carrier for the terminal, the component carrier to he used by

the terminal is determined at least according to a rule that is decided by a distribution mode in the case that a distribution of coverage range of different available carriers corresponding to the position of the terminal accords with the predetermined distribution mode, wherein the predetermined distribution mode and corresponding rule is one of:
the predetermined distribution mode is that the coverage ranges of different available carriers are substantially the same, and the rale comprises taking each available carrier as a candidate component carrier;
the predetermined distribution mode is that there exists at least one available carrier the coverage range of which is substantially contained within the coverage range of at least one other available carrier, and the rule comprises determining a candidate component carrier at least according to the size of the coverage range of each available carrier; and
the predetermined distribution mode is that there exist at least two available carriers the coverage ranges of which are substantially not coincident with each other nor contained one in the other but overlapped with each other, and the rule comprises determining a candidate component carrier at least according to a position where the terminal is located and a moving direction and moving speed of the terminal.
19. The terminal as claimed in claim 18, wherein the new secondary component carrier is in a deactivated state after being added.
20. The terminal as claimed in claim 18, wherein the base station is configured to acquire status information of a terminal, a base station and/or a component carrier, and determine to update the secondary component carrier in case of the status information satisfying a predetermined condition.
21. The terminal as claimed in claim 20, wherein the predetermined condition comprises that updating of the secondary component carrier is required for a service or is required for
the original base station inconsideration of an overall load balance of the network or inter-user interference.
22. The terminal as claimed in claim 20, wherein the predetermined condition comprises
that a signal over the old secondary component carrier is degraded in quality.

23. The terminal as claimed in claim 20, wherein the predetermined condition comprises that the terminal moves beyond a coverage are of the old secondary component carrier or moves into ac coverage area of a new base station.
24. The terminal as claimed in claim 21, wherein the predetermined condition comprises that an amount of physical resources over the unlink and downlink of the old secondary component carrier is insufficient.
25. The terminal as claimed in claim 18, wherein the component carrier to be used by the terminal is further determined according to other factors with different priorities in determination.
26. A method for updating a secondary component carrier in a carrier aggregation communication network, comprising:
receiving "Radio Resource Control" reconfiguration information from a base station; and
configuring a new secondary component carrier with radio resource configuration information comprised in the "Radio Resource Control" reconfiguration information,
wherein mobility control information is not included in the "Radio Resource Control" reconfiguration information, configuring the new secondary component carrier being executed without reconfiguring of MAC or updating of security key and
receiving an activation command transmitted from the base station to activate the new secondary component carrier, whereby the secondary component carrier is updated by adding a new secondary component carrier or replacing an old secondary component carrier with a new secondary component carrier, determining the component carrier to be used by the terminal at least according to a rule that is decided by a distribution mode in the case that a distribution of coverage range of different available carriers corresponding to the position of the terminal accords with the predetermined distribution mode, wherein the predetermined distribution mode and corresponding rule is one of:
the predetermined distribution mode is that the coverage ranges of different available carriers are substantially the same, and the rule comprises taking each available carrier as a candidate component carrier;

the predetermined distribution mode is that there exists at least one available earner the coverage range of which is substantially contained within the coverage range of at least one other available carrier; and
the rule comprises determining a candidate component carrier at least according to the size of the coverage range of each available carrier: and the predetermined distribution mode is that there exist at least two available carriers the coverage ranges of which are substantially not coincident with each other nor contained one in the other but overlapped with each other, and the rule comprises determining a candidate component carrier at least according to a position where the terminal is located and a moving direction and moving speed of the terminal.
27. A communication system, comprising the base station as claimed in any one of claims 1 to 9 and the terminal as claimed in claims 18 to 25.