Evolving Cell Sites to Multi-Service Cell Sites

In the early days with 2G networks, cell sites were primarily designed around circuit switched TDM Based connectivity and responsible for enabling voice traffic.  As networks transitioned to 3G and 4G, cell sites were upgraded to carry IP based traffic for both voice and data traffic.  This upgrade of cell site functionality aligned well with the profitability of network operators.  The networks which were aggressive in this transition of their cell site technical capabilities enabled the coincided profitability.  With 5G around the corner, the role of cell sites will be even more crucial.  It plays a critical role in adding new revenue streams, enhancing network operator's current offerings and ultimately building the business case for 5G adoption.   Cell sites need to evolve to a multi-service cell site to offer new revenue generating services like B2B service for Small Enterprises and SMB customers, enhanced user experience for social media and streaming services, public safety applications, IOT/Smart City applications and far edge use cases.

For the multi-service cell site -it's table stakes to deliver much higher bandwidth, better resiliency and significantly lower latency.  However, most of the cell sites are being deployed with sub-optimal architectures based on layer 2 technologies. While layer 2 solutions generally result in lower CapEx, they tend to have higher OpEx and are extremely restrictive in terms of new service creation.  To realize the full potential of the 5G cell site, it's critical to bring layer 3 technologies to the cell site.  Backhaul networks have already evolved from MPLS-TP / TDM to  layer 3/IP-MPLS/SR .  Extending these technologies to enable the multi-service cell site will bring significant benefits to the possible services which can be delivered.

Cisco Converged 5G Transport

Let's look at some of the key benefits of such an evolved architecture:

Robust Infrastructure: The infrastructure which enabled 3G/4G will not be sufficient to fully realize the potential of the multi-service cell site.  It needs to be secure, redundant, reliable, scalable and programmable.  Any compromise on these aspects can result in sub-optimal performance of the network. Using routers that are layer 3 based devices at the cell site enable:

• Site sharing and densification
• Best in class timing capabilities with Class C precision and SyncE up to the cell site
• Carrier-Class reliability and redundancy
• Consistent OAM end to end
• Trustworthy system with complete visibility of device security health

Service Agility: As we look ahead and build the business case for investing in 5G, every network port in the cell site would be viewed as service port.  Uniform function availability, flexibility and consistency of features will be of the utmost importance.  The gateway device at the cell site should have the capability of network slicing, service demarcation, quality of service, monitoring capabilities of service, and seamless integration. The multi-service cell site router provides all of these capabilities mentioned along with:

• Ease of integrating the 5G Core with AMF/SMF/UPF.
• End to End network slicing
• Seamless service provisioning & workflows
• Consistent QoS across the network
• Consistent service monitoring across the network

Operational benefits: Apart from the required CapEx investment and validation of the business case for new revenue generating streams, the subject of Operational Expenditure has also been primary part of the 5G journey.  It is now unfathomable to build a network which relies on manual intervention apart from the actual physical deployment of the network.  Using a router at the cell site enables congruency and alignment with the rest of the network resulting in seamless operatons. Consistent tools cross the network coupled with common protocol and operating environments allow for stronger control over the network.  While the backhaul and edge networks have been employing network automation capabilities for a while, the cell site has been left out frequently due to disjointedness of the solutions being deployed.  Ironically, the sheer quantity and potential remoteness of the cell site deployment dictate even more criticality to use an automation-first approach for the cell site.  Features like Zero Touch Provisioning (ZTP) and telemetry reduce the operational burden and increase network visibility while creating:

• End to End automation and tighter integration with backhaul networks
• End to End layer 3 for consistent reporting and analytics
• Reduction in network touch points

I would highly recommend to read the Converged 5G  xHaul Transport whitepaper and 5G Transport Technical Case Study to dig deeper into these concepts.

In summary, the future of the cell site lies clearly with the move to routing foundation. While there is dependency on the fiber availability at the cell site, that gap will be closed quickly with most service providers moving quickly with fiber deployments.   Today, a router typically aggregates 5 to 10 cell sites.  However, as fiber availability increases, we will see an increase in demand of routers at every cell site.  As one of the leaders in the 5G converged transport space, Cisco has heavily invested in developing cost-effective and ruggedized full feature routers for cell site deployments which is demonstrated byone of the largest service providers in Asia deploying Cisco's cell site routers at every cell site location.  Join the party, 5G and the dawn of the multi-service cell site router is here.

For more information :

Sprint Strengthens Its IP Mobile Network for 5G with Cisco

Indosat brings Converged SDN Transport Network to Indonesia

Cisco Network Convergence System 540 Series