Overview
As mobile operators transition to 5G, careful planning of network and gNB (Next Generation Node B) deployment is crucial. The aim is to balance operational costs and ease of deployment while accommodating existing network architectures and service demands. So, now let us see How to Optimize 5G gNB Deployment Options along with Accurate LTE RF drive test tools in telecom & RF drive test software in telecom and Accurate 4G Tester, 4G LTE Tester, 4G Network Tester and VOLTE Testing tools & Equipment in detail.
The 3GPP Interface and Centralized Units
The 3rd Generation Partnership Project (3GPP) has introduced a new interface within the 5G radio node’s baseband. This interface allows splitting the gNB’s baseband hardware, enabling parts of the baseband functionalities to be centralized. This centralized approach enhances cooperation between neighboring nodes, previously requiring direct cell site communication, by managing it within the baseband unit’s centralized part.
Challenges in 5G gNB Deployment
Higher Layer Split (HLS/F1-Interface) vs. Lower Layer Split (e-CPRI/CPRI Interface)
While the HLS/F1-interface has similar transport requirements to the S1 interface used in 4G, the low layer split (e-CPRI or CPRI interface) demands stringent bandwidth and latency standards for the transport network. Despite using Ethernet on Layer 2, the e-CPRI interface cannot be aggregated via an Ethernet switch or IP router due to its strict latency and jitter requirements. Consequently, each radio unit would require dedicated fiber or wavelength, which can be cost-prohibitive.
Fiber and Wavelength Considerations
To reduce the number of fibers or wavelengths, chaining of Remote Radio Heads (RRH) can be considered. However, Small Form-factor Pluggables (SFPs) used for chaining can be expensive. Additionally, centralized geo-redundancy of the baseband would double the number of fiber links per wavelength, making the deployment less cost-effective. Therefore, low layer split is typically not feasible for widespread network deployment, except in specific industrial or campus network scenarios during the early 5G gNB deployment phase.
Early 5G Deployment Strategies
Early 5G deployment focuses on traditional methods. Most current 4G cell site connections use 1 Gigabit Ethernet (1GE) fiber or microwave links. Upgrading these connections to at least 10GE is recommended when adding a 5G gNB to a 4G site. During this phase, using multi-standard base stations or 5G gNBs for traffic aggregation is not advised due to the immature nature of 5G software, which will require multiple updates and patches for optimal performance. Ensuring that 4G operations remain unaffected during these upgrades is crucial.
Addressing Network Upgrades
Many existing eNBs (evolved Node B) are equipped with only 1GE interfaces, making it impossible to route 5G traffic through these 4G eNBs unless they have been upgraded to 10GE. For geo-redundant connections, introducing a dedicated Cell Site Gateway (CSG) to aggregate traffic from both the eNB and 5G gNB to a common transport link is the most standardized solution. The CSG can also facilitate a radio vendor-independent geo-redundancy solution, aggregating traffic from microwave hubs and providing consistent geo-redundancy for nodes connected via microwave.
X2/Xn Interface Implementation
Currently, not all vendors support this; some use proprietary links between radio nodes, forcing the use of 5G gNBs from the same vendor as the 4G eNB, which is less flexible. Small cell deployments, typically non-standalone (NSA) and anchored by 4G macro sites, also face challenges if a back-to-back link is not feasible.
Minimizing Complexity
To enhance cooperation features between radio nodes, minimizing complexity is essential. Routing traffic as close to the cell site as possible and directly routing X2/Xn interfaces on the CSG or microwave tree are recommended. Implementing routing capabilities on the CSG, rather than relying on Layer 2 solutions, prevents the need for extensive IP address re-planning and site-specific subnet sizes.
Dynamic vs. Static Routing
Implementing Layer 3 (L3) routing functionality at the CSGs is advisable. Dynamic routing protocols between the CSG and mobile backhaul can optimize network performance, especially for geo-redundant connections. While static routing suffices for regular traffic, dynamic routing for X2/Xn interfaces ensures the shortest path via the backup metro router, minimizing delay and enhancing overall latency.
Conclusion
Optimizing 5G gNB deployment requires a nuanced approach that considers existing infrastructure, service demands, and operational costs. While traditional methods serve well during the early deployment phase, advancements in centralized unit architectures, CSG implementation, and dynamic routing will play pivotal roles in enhancing network efficiency and performance. By strategically planning and adopting innovative solutions, mobile operators can effectively meet the challenges and demands of 5G deployment. Also read similar articles from here.