Distributed Base Station System and Method for Networking thereof and Base Band Unit

Abstract

The present invention discloses a distributed base station system as well as its networking method and base band unit. In this system, the base band unit (BBU) and RF unit (RFU) of the base station are separated, and the RFU is equipped with base band RF interfaces for interconnecting the BBU and transmitting data information, thereby forming the base station. Based on the separation of the BBU from the RFU, the BBU capacity is further divided at the same time, and every unit is also arranged independently. The BBU networking and capacity expansion may be achieved with capacity expansion interfaces and base band RF interfaces provided by BBU interface units in flexible and convenient ways.

1 . A distributed base station system, comprising:
 a first base band unit (BBU) in communication with a radio frequency unit (RFU);   wherein the first BBU comprises:
 a main processing unit; 
 a clock unit; 
 a base band signal processing unit; 
 a transmission unit; and 
 an interface unit; 
   wherein the interface unit is configured to:
 intercommunicate digital base band signals with the base band signal processing unit; and 
 intercommunicate master control information with the main processing unit; 
   wherein the interface unit comprises a primary base band radio frequency (RF) interface;   wherein the RFU comprises a secondary base band RF interface and the RFU is connected to the primary base band RF interface of the BBU;   wherein the distributed base station system further comprises at least a second BBU;   and wherein the interface unit of the first BBU further comprises a capacity expansion interface, configured to communicate with the second BBU.   
     
     
         2 . The system according to  claim 1 , wherein the primary base band RF interface and the secondary base band RF interface both are high speed digital interfaces. 
     
     
         3 . The system according to  claim 1 , wherein the capacity expansion interface is further configured to transmit the master control information from the first BBU to the second BBU. 
     
     
         4 . The system according to  claim 3 , wherein the first BBU connects with the second BBU via wire cable or optical fiber, and wherein the capacity expansion interface comprises a primary capacity expansion interface that provides an active/standby switchover control signal. 
     
     
         5 . The system according to  claim 3 , wherein the interface unit further comprises an identification interface for marking the type of the base station and the position of the BBU. 
     
     
         6 . The system according to  claim 3 , wherein the interface unit further comprises a dry contact input interface for expanding the input dry contact functions of the base station. 
     
     
         7 . The system according to  claim 3 , wherein the first BBU and the second BBU comprise: a master BBU in an active state and a standby BBU in a standby state. 
     
     
         8 . The system according to  claim 3 , wherein the RFU is connected with any one of the first BBU and the second BBU. 
     
     
         9 . The system according to  claim 1 , wherein the first BBU and second BBU comprise a slave BBU that works in a slave state. 
     
     
         10 . The system according to  claim 1 , further comprising: an exchange base band (BB) cassette with a plurality of capacity expansion interfaces;
 wherein the first BBU is connected with a capacity expansion interfaces of the exchange BB cassette via the capacity expansion interface of the first BBU; and   wherein the second BBU is connected with another capacity expansion interface of the exchange BB cassette.   
     
     
         11 . The system according to  claim 1 , wherein the main processing unit, the clock unit, the base band signal processing unit, the transmission unit and the interface unit are integrated in a BBU cassette. 
     
     
         12 . The system according to  claim 1 , wherein the capacity expansion interface is further configured to transmit the base band signals from the first BBU to the second BBU. 
     
     
         13 . The system according to  claim 1 , wherein the capacity expansion interface is further configured to transmit transmission information from the first BBU to the second BBU. 
     
     
         14 . A base band unit (BBU), comprising:
 a main processing unit;   a clock unit;   a base band signal processing unit;   a transmission unit; and   an interface unit;   
       wherein the interface unit is configured to
 intercommunicate digital base band signals with the base band signal processing unit; and 
 intercommunicate master control information with the main processing unit; 
 
       wherein the interface unit comprises a primary base band RF interface, configured to connect with a radio frequency unit (RFU);
 wherein the interface unit of the BBU further comprises a capacity expansion interface, configured to communicate with another BBU. 
 
     
     
         15 . The base band unit according to  claim 14 , wherein the primary base band RF interface is a high speed digital interface. 
     
     
         16 . The base band unit according to  claim 14 , wherein the interface unit further comprises an identification interface for marking the type of a base station in which the BBU belongs and the position of the BBU. 
     
     
         17 . The base band unit according to  claim 14 , wherein the interface unit is further configured to transmit the master control information or the base band signals from the BBU to the other BBU. 
     
     
         18 . The base band unit according to  claim 17 , wherein the interface unit further comprises at least one of:
 a reset interface for resetting a base station in which the BBU belongs;   an identification interface for marking the type of the base station and the position of the BBU;   a power supply switches for controlling power on and power off for the base station;   a test interface for connecting the BBU with an external test equipments;   a signal input interface for receiving external clock signals;   a dry contact input interface for expanding input dry contact functions of the base station;   an electrostatic discharge (ESD) connector; and   a protect ground (PGND) terminal.   
     
     
         19 . The base band unit according to  claim 17 , wherein the capacity expansion interface comprises one or a plurality of capacity expansion interfaces for providing an active/standby switchover control signal. 
     
     
         20 . The base band unit according to  claim 18 , wherein the signal input interface comprises a signal input interface for receiving global positioning system (GPS) synchronous clock signals and/or a signal input interface for receiving 2M synchronous clock signals. 
     
     
         21 . The base band unit according to  claim 18 , wherein the test interface comprises at least one of a 10M test interface for outputting 10M test synchronous clock signals and a transmission time interval (TTI) test interface for outputting TTI signals. 
     
     
         22 . The base band unit according  claim 14 , wherein the main processing unit, the clock unit, the base band signal processing unit, the transmission unit and the interface unit are integrated in a BBU cassette. 
     
     
         23 . The method according to  claim 14 , wherein the BBU and the other BBU are interconnected via wire cable or optical fiber. 
     
     
         24 . The method according to  claim 14 , wherein the BBU and the other BBU are interconnected via an exchange BB cassette. 
     
     
         25 . A communication method between a first BBU and a second BBU in a distributed base station, wherein the first BBU comprises a main processing unit and a capacity expansion interface, the method comprising:
 obtaining master control information from the main processing unit of the first BBU;   transmitting the master control information from the first BBU to the second BBU via the capacity expansion interface of the first BBU.   
     
     
         26 . The method according to  claim 25 , further comprising:
 transmitting master control state report information from the second BBU to the first BBU.   
     
     
         27 . The method according to  claim 25 , wherein the first BBU and the second BBU are interconnected via wire cable or optical fiber;
 wherein the first BBU is set as a master BBU, and the second BBU is set as a slave BBU.   
     
     
         28 . The method according to  claim 25 , wherein the first BBU and the second BBU are interconnected via wire cable or optical fiber;
 wherein the first BBU is set as a master BBU, and the second BBU is set as a standby BBU.   
     
     
         29 . The method according to  claim 28 , further comprising;
 degrading the first BBU to standby BBU when the main processing unit of the first BBU fails; and   upgrading the second BBU to a master BBU.   
     
     
         30 . The method according to  claim 25 , further comprising:
 transmitting downlink data from an radio network controller (RNC) to the first BBU;   transmitting the downlink data from first BBU to the second BBU via the capacity expansion interface.   
     
     
         31 . The method according to  claim 25 , further comprising:
 transmitting uplink data from an remote radio unit (RRU) to the first BBU;   transmitting the uplink data from first BBU to the second BBU via the capacity expansion interface.   
     
     
         32 . The method according to  claim 25 , wherein the first BBU and the second BBU are interconnected via an exchange BB cassette;
 wherein the first BBU is connected with a capacity expansion interface of the exchange BB cassette via the capacity expansion interface of the first BBU; and wherein the second BBU is connected with another capacity expansion interface of the exchange BB cassette.   
     
     
         33 . The method according to  claim 32 , wherein the transmitting the master control information comprises:
 transmitting the master control information from the first BBU to the exchange BB cassette; and   transmitting the master control information from the exchange BB cassette to the second BBU.   
     
     
         34 . The method according to  claim 32 , further comprising:
 transmitting uplink data from the first BBU to the exchange BB cassette; and   transmitting the uplink data from the exchange BB cassette to the second BBU.   
     
     
         35 . The method according to  claim 32 , further comprising:
 transmitting downlink data from the first BBU to the exchange BB cassette; and   transmitting the downlink data from the exchange BB cassette to the second BBU.