RF Unit CPRI Interface Error alarm in Huawei DBS 3900

The Common Public Radio Interface (CPRI) standard defines the interface of base stations between the Radio Equipment Controllers (REC) in the standard, to local or remote radio units, known as Radio Equipment (RE). In parallel with standard optical transceivers, special purpose optical transceivers are being manufactured. One of them is optical transceiver for CPRI. There are times when Huawei DBS 3900 produces an following error alarm:


RF Unit CPRI Interface Error

It happened when CPRI 2.67G-SFP-2D transceiver is used in this device. This error leads to a serious problem – not working link. In this case problem is in SFP module EEPROM memory map. The optical transceiver coding has receiver slew and receiver filter functions enabled – but in this case they should be disabled. Receiver slew and filter modes controls the bandwidth. If they are enabled then biggest bandwidth can be supported is only 2.25 Gbits as a result this causes error in Huawei DBS 3900. This lesson is learned and now we can provide support of CPRI 2.458 Gbps support on this family of transceivers.