Synchrony for Enterprise 5G
Overlooking the vast waterways of Surma plains in the north eastern part of Bengal delta, I observed a natural phenomenon in my childhood that till date vivid in my mind. As migratory birds flock over the waterways during the twilight of dawn and dusk, they appear to maintain a natural symmetry of forming a sign wave across the distance horizon. The waves of flocks are seemingly phase aligned.

We rarely think about this naturally occurring phenomena when it comes to the design of network infrastructure, yet it is something de-facto in how communications devices work in a synchronicity. Whether a network is homogenous or heterogenous, imperatives of synchronicity cannot be overlooked, nor it can be ignored. Every device in a network from computers to routers, an inherent synchronization is in work by design thanks to the advent of oscillators for local reference and NTP for distributed synchrony. For many of us looking under the hood is not something we do often when it comes to designing the network. However, given the increased applications of time-sensitive transport in different industry verticals, synchronicity can no longer be assumed or overlooked. It is especially true for 5G deployments due to its common use of TDD spectrums in the Radio Access Network (RAN).

The case for Synchronicity in Enterprise Network

Today, an enterprise network is more hybrid, having a mix of homogeneous and heterogeneous applications that are distributed across the network. Let’s take a conventional distributed database system for example. Enterprise can no longer be able to afford having centralized coordination of stateful data scaling out within a centralized data center [1] where specific design assumptions are applied to control the network environment. Even in such circumstances common use of NTP based synchronization no longer serves the purpose of concurrency control. Moreover, enterprises are now on the verge of accepting the reality of edge and the challenges of heterogeneity that comes with it. 

Figure 1. Synchrony for Geo distributed database in Enterprise Network.

Figure 1. Synchrony for Geo distributed database in Enterprise Network.

Organizations are global today than ever before, and their operations are geographically distributed. Conventional distributed databases no longer serve the purpose of horizontal scalability, transactional consistency for geo distribution and geographically distributed data residency. The choice is a geo distributed database one that takes into context the complexities of time series data input at the edge, maintains data sovereignty compliance with data residency and transactional integrity [2] of geo-partitioned databases. With this geo distributed database requires a distributed sync plane that maintains highly precision traceable primary clock reference for end to end data-path. Some hyperscalers such as Google have addressed this issue of distributed synchrony with the “true time” API for their geo distributed database service “Cloud Spanner”. While enterprises can leap on solutions such as geo distributed cloud database services, there are numerous scenarios in which having resident geo distributed databases or hybrid solutions thereof are more beneficial. For the later, the importance of distributed synchrony cannot be ignored. Moreover, enterprises need distributed synchrony for many other applications e.g. CBRS and plant operations etc.

Synchronicity for Private Enterprise 5G

  Delivering better cellular coverage and network mobility support to geographically distributed enterprise locations provide tremendous benefits to enterprises, from manufacturing to logistics and fleet operations. More of us are familiar with private LTE that has been increasingly penetrating enterprise networks over the last few years. Enterprise 5G a step ahead of private LTE delivering better bandwidth, reliability and inherent support for URLLC infrastructure. Furthermore, enterprise 5G can decide how to manage third-party traffic from operators or other service providers without disrupting its own traffic [3]. Interestingly 3GPP band 48 with a spectrum of 3.5GHz offers a great choice for enterprise 5G solutions. Known as CBRS (Citizen Band Radio Service), this new band offers open access to a 150MHz spectrum for use by enterprises. This service can be obtained by CBRS solutions providers who provide open access to 150MHz by using a scanning service known as SAS (Spectrum Access System) which protects against interference from higher priority users. CBRS uses TDD spectrum and thus requires high precision distributed time sync to deploy CBRS.

Figure 2. CBRS deployment as Enterprise 5G solution.

Figure 2. CBRS based Enterprise 5G deployment

Some solutions offer a mix of LTE-A and 5G TDD spectrum allowing booth coverage and high bandwidth of up to 300 Mbps. A number of radio endpoints can be deployed in each floor of the corporate building enhancing multiservice transport capabilities over CBRS spectrum. In certain sectors (such as healthcare, hospitality, retail and manufacturing) CBRS is ideal and offers unmatched performance for mission critical applications. However, irrespective of CBRS deployment scenario distributed high precision synchronicity is a must.

Conclusion

Business users are increasingly adopting 5G for a myriad of use cases depending upon industry verticals: smart manufacturing, smart grid, healthcare, hospitality and retails. For this, high precision synchronization is inherent and must be considered beforehand prior to deployment. Moreover, today’s enterprise heterogeneous network cannot ignore the synchrony for many other applications from geo distributed databases to application of machine visions. Given the increasing need for high precision synchrony, a strategy for enterprise network synchronicity should include a clustered approach for secured resilient timing as well as geo distributed synchrony to support a myriad of geographically distributed applications. 

Reference

1.    Section, 2020. The Challenges of Distributed Databases at the Edge. Section.io.

2.    Lamb, C., 2021. The Guiding Principles for Cloud-scale, Geo-distributed Databases. DATABASE JOURNAL.

3.    Paolini, M., 2019. CBRS: Should the enterprise and venue owners care? Senza Fili. 

Author: Dhiman Deb Chowdhury