Skip to 0 minutes and 9 seconds The radio environment behaves differently in each of the frequency bands we previously introduced. Physics dictates that the higher the frequency, the smaller the coverage for the same power transmitted from the base-station. So service providers prefer to get allocation of the lower frequency bands like 800 or 900 MHz, because they can then cover a given area with fewer base-stations. Radio Network deployment is a multi-step process. Two of the important steps in this process are Radio Network Planning, followed by RAN Optimization. In the next slides we will learn more about each step. The goal of Radio Network Planning step is to create a network that will provide the users with wireless services available everywhere, anytime and in good quality.
Skip to 1 minute and 7 seconds The network engineering team plans the network to achieve the desired coverage in different areas of the country. This means that a subscriber should not experience a no service indication in these areas. The engineers use a planning tool to place base stations in different locations on a map and set their relevant parameters like output power and antenna height and direction. Then they run a simulation in the tool that provides a coverage map. This process will be repeated several times until the desired coverage is achieved. Another step in the RAN planning process is to verify that the planned network has sufficient capacity to support the estimated number of subscribers.
Skip to 1 minute and 57 seconds The engineers take into consideration the subscriber usage profile; how many voice calls, video downloads, web browsing sessions, etc., whether he is indoors or outdoors, whether he is a pedestrian or in a car, and more. They also account for subscriber distribution in the network – dense urban areas, rural areas, etc. All these inputs are used in the simulation to see how the network will behave when it will be loaded with users. The engineers can assign variable capacity resources to each base station to support the estimated capacity in the busy hours and in quieter hours.
Skip to 2 minutes and 41 seconds To summarize the RAN planning phase, the engineers use a planning tool to run theoretical simulations of the network behavior when loaded with users, making use of mathematical models and algorithms.
Skip to 2 minutes and 55 seconds The output of this phase is: a set of maps showing the coverage and available capacity in all areas, a list of base station geographical locations (latitude and longitude), a recommended configuration for each base station with the relevant parameter settings. The base stations are then deployed in locations as close as possible to the recommended ones. However, sometimes, due to restrictions or challenges in finding the exact locations, new locations are used in the vicinity of the recommended ones. The real site locations in the field are imported back into the planning tool, and the engineers analyze the impact of the site location changes and get an updated set of coverage and capacity maps.
Skip to 3 minutes and 50 seconds Once the network is deployed and subscribers start using it for voice and data sessions, a process of network monitoring begins. The network behavior is dynamic and changes throughout the day. For example, during rush hour the major highways are congested in comparison to other hours of the day, or in shopping malls there are more people during the weekend than during the mornings on week days. This dynamic behavior creates a gap between the theoretical network planning output and what really happens in the network. This gap has to be analyzed and addressed so that the service provider can provide the required capacity, coverage and quality expected by the subscribers.
Skip to 4 minutes and 35 seconds The process of fine-tuning the network based on inputs from the field, is called RAN Optimization. The optimization engineers collect data from the base stations and other nodes, which includes performance information such as number of dropped calls or access failures. Additionally, call logs are collected from the network, which include specific events that occurred during each call or session in the base station. By analyzing the collected data, the engineers can identify problems in the network and make adjustments and changes to resolve them. They change base station power settings, antenna-related settings and other parameters in order to achieve the best coverage for the most users while maintaining the best achievable quality of experience for their subscribers.
Skip to 5 minutes and 28 seconds Here we have an example of a coverage map based on call logs collected from the network. The green and blue dots represent good coverage and the yellow and red dots represent poor coverage. The optimization engineer will focus on turning the red and yellow dots into green by changing power settings in the base stations that serve these problematic areas. In this example we see the coverage area of the encircled base station. These are the red and yellow dots that we see on the map. If we look at the bottom of the picture, we see the antenna installed in the base station and the tilt it has configured.
Skip to 6 minutes and 10 seconds We also see the layout of the terrain and the coverage area of the specific antenna. The area encircled in blue shows us that the base station is over-shooting, meaning that it is providing coverage in a further away location that was not planned for and this can cause degradation in the quality of sessions in that area. The optimization engineer will change the antenna tilt so that it will no longer provide coverage to that area.
Demystifying Radio Network Engineering
What is Radio Network Engineering? What is network deployment and what needs to be considered when deploying a network? Find out where planning and optimization fit into the picture.