By Geng Jianxu & Ma Bin
Microwave network bandwidth is expanding rapidly; comprehensive, dedicated optimization support is needed if increasingly IP-based network architecture is to be best leveraged.
Ultra-broadband microwave network service is increasingly being handled on an IP-basis, but this transition is proving very challenging for operators and vendors alike, as service downtime must be minimized, QoS assured, and costs reduced. A systematic, customized optimization service that covers measurement, implementation and delivery tools is needed; the key elements of this service would be legacy network evaluation, network planning, and third-party services.
Three key elements
Assessment of current network KPIs
Though cost-effective, microwave transmission is quite sensitive, it can be hampered and even interrupted by obstructions and inclement weather conditions such as rain, snow, and fog. A network evaluation system with a complete set of real-life KPIs would help operators collect network performance data in real time, which would then be analyzed to reveal bottlenecks, redundancies, and other flaws.
Planning network targets
Network optimization is not an academic activity; operators have a business to run. Network planning must be comprehensive and creative, as microwave network migration may involve network combination or site/cluster relocation; both require customized services. Security and feasibility indices must also be simulated if a plan is to remain useful by the time the new network is implemented. Above all, target planning must keep in mind as the downtime must be minimized as much as possible.
Catering to multi-vendor infrastructure
Microwave network hardware typically is purchased from multiple vendors, so a network optimization service must be vendor-agnostic, or at least flexible. The service provider must understand the networking architecture and configurations/protocols that each vendor employs so that it can collect data accurately and extend network management system (NMS) coverage. The provider must also have a robust analysis capability, as it will be dealing with data in varying formats.
Enhanced network optimization service
Years of experience have yielded the tools with which Huawei offers a complete solution set for microwave network optimization, suitable for any phase of network evolution, including current state evaluation, LOS survey, network planning, project delivery, and network migration planning. With its refined methodology and real-world KPI system, Huawei can help evolve a network towards a specific target, or it can optimize on a more general basis.
Comprehensive KPIs that matter
If microwave network upgrade is to prove successful, a network's performance, capacity, resource usage, and redundancies must be well understood. Details relevant to upgrade might include the number of empty subrack slots, vacancies for new antennas, and port bandwidth upgrade compliance for intermediate frequency boards. Huawei has established dual KPI systems that cover either performance or comprehensiveness. Overall, more than forty items are indexed into seven categories, so that any microwave network can be analyzed in a refined and quantitative manner.
Performance covers eight indices, including link availability, fade margin (FM), and unavailable second (UAS), all of which reflect microwave link availability (typically ranging from 99.995 to 99.997%) and provide references for link optimization and capacity expansion. Comprehensive indices are intended to reflect overall network status in terms of capacity, frequency, topology, or resources.
These indices help identify utilized/idle network resources and network bottlenecks, while facilitating long-term optimization preparation. Both index categories help operators manage their network status and optimize accordingly.
Efficient optimization tools
Huawei has also developed a series of tools, including Pathloss, Eplise, Designer, and the AMS5000, to facilitate network evaluation, network planning and project implementation. These tools enable network data collection, KPI analysis, air interface design, service planning, and equipment migration, while greatly enhancing network efficiency and quality; they are suitable for most key elements of microwave network optimization.
First, the AMS5000 collects live network data, evaluates network KPIs, and creates reports that aid the drafting of network optimization schemes. It can then simulate the target network, adjust relevant parameters, and update the overall plan accordingly. After this plan is confirmed, tools such as Pathloss and Eplise can be used for air interface design, with Designer used for service design. Throughout the entire process, Huawei service teams cooperate with licensed partners to deliver these optimization services in a timely and efficient manner.
Efficient third-party migration
Huawei network optimization services cover third-party equipment evaluation and migration; with said migration divided into three phases. First, data concerning network topology, equipment structure, and radio protection configuration is collected and analyzed. Second, network planning schemes that minimize downtime are drawn up; and third, project management and delivery are carried out, with legacy equipment reused as much as possible.
Huawei has successfully carried out network optimization for over 100 operators; twenty of these projects focused on microwave, including those for Ufone and CMPAK (Pakistan), as well as AxB (Bangladesh). Huawei also has over 100 microwave network migrations under its belt, including projects for Globe (the Philippines).
As an example, a certain operator had commenced its network deployment in 2001 with support from multiple vendors, gradually building a microwave network of over 6,000 hops. Network upgrades, however, did not bring enhanced user experience; it actually brought lowered KPIs, degraded multi-hop link performance, and antenna overloading. In addition, its legacy networks were TDM-microwave, which could not meet the needs of its booming wireless data services; upgrade was clearly necessary.
This operator partnered with Huawei for phased optimization of its microwave infrastructure. Huawei helped the operator evaluate over 20 KPI items, re-plan the network topology, adjust tower loads, identify & eliminate frequency interference, remove network bottlenecks, and reuse/migrate legacy equipment. As a result, network performance has been significantly enhanced.
With its experience and competence, Huawei was able to provide a competitive microwave network, which now forms the wireless backhaul foundation for this operator's plans to be a leading carrier in its region.