As conventional microwave frequency bands (6–38 GHz) have a small bandwidth (generally less than 112 MHz), ODU hardware stacking used to be the only way to multiply the bandwidth prior to the advent of CA. Now with CA, high-bandwidth transmission is achieved by aggregating multiple channels in one ODU device. Due to hardware and other limitations, existing CA ODUs have stringent requirements on the range of spectrum that can be aggregated and therefore only support a narrow CA instantaneous bandwidth (IBW). For the 112 MHz spectrum, CA can be used on adjacent channels only; for spectrum exceeding the CA IBW, high bandwidth can only be achieved through hardware stacking.
To address these challenges, Huawei developed XMC-5D Pro — the next-generation wideband CA ODU. The solution uses innovative wideband technology to increase ODU CA IBW from 224 MHz to up to 800 MHz, thereby expanding the range of aggregatable spectrum by around four times. This solves the problem that a single CA ODU cannot aggregate discrete spectrum and greatly expands the scenarios where CA can be deployed. The solution also uses next-generation high transmit power technology to increase the transmit power of the wideband CA ODUs by 3 dB, which reduces the antenna diameter by one level. This reduces installation space and load-bearing capacity requirements for towers, making deployment easier and faster.
The innovative commercial link was deployed in downtown Hohhot using 23 GHz XMC-5D Pro ODUs, which are in 4+0 configuration and each aggregates four 112 MHz spectrum, supporting a maximum bandwidth of 5 Gbit/s. The deployment is easy and achieves great results — the link runs stably and provides excellent service experience.
Commenting on the commercial use, Zhang Chengliang, Director of China Unicom Inner Mongolia’s Network Department, remarked: “Microwave backhaul is key for us to improve user experience in Inner Mongolia. Huawei’s next-generation wideband XMC-5D Pro ODUs and other microwave products help improve the bandwidth and quality of suburban networks while at the same time reducing hardware, power consumption, and TCO, thus better allowing us to build wireless networks.”