IEEE 1588 PTP and SyncE protocols keep radio units, switches, and distribution units in sync.
Deployment of 5G networks in cities around the world marks one of the largest and fastest evolutions in networking infrastructure. To inspire competition and innovation, the open radio access network, or Open RAN, is an industrywide initiative to enable interoperability among hardware suppliers. The standardization of Open RAN levels the playing field, driving lower costs with more competition while letting operators mix and match components for best performance. Network providers, and by extension consumers, will welcome decreased costs from interoperability. The growing number of components that need synchronization brought on by the densification of the network makes careful consideration of network timing functions critical.
The OPEN RAN architecture consists of three major components: the remote radio unit (RU), the fronthaul switch, and the distribution unit (DU), shown in Figure 1. The RU serves as the consumer’s access point to the network. The DU acts as the connection to the centralized unit (CU) and the mobile core. Finally, the fronthaul switch routes traffic between the RU and DU. The standardized interface that transmits information between components of the radio access network is known as enhanced Common Public Radio Interface (eCPRI). These components need precise synchronization to avoid data packet loss and network interruptions.