Introduction to RAN and the Need for Open RAN
Fundamentals of Radio Access Networks (RAN): Basic components and functions.
There are 5 major components to RAN (Base Stations, Antennas, Radios, Baseband Units, and User Equipment)
1. Base Stations (BS):
The main point where your phone connects to the network. It handles radio signals and keeps everything running smoothly in that area.
2. Antennas:
Antennas send and receive wireless signals . They also help decide how far the signal goes and how strong it is.
3. Radios:
Radios turn digital data into radio waves so it can travel wirelessly. They also make sure the signal uses the right frequency and power.
4. Baseband Units (BBUs):
Baseband Units act like the brain of the base station. They clean up the signal, check for errors, and help keep your connection fast and safe.
5. User Equipment (UE):
This is your phone, tablet, or any device that connects to the network.
Functions of the RAN:
Radio Resource Management: Controls things like signal strength, time, and frequency so everyone gets a good connection.
Handover Management: Makes sure your call or video doesn’t drop when you move between towers.
Interference Management: Reduces signal problems caused by overlapping signals from other users or towers.
Network Optimization: Keeps the network running its best by adjusting settings based on how people are using it.
Backhaul: Moves your data from the base station to the main internet network.
How It Works:
- Your phone sends a signal when you make a call, send a message, or use the internet.
- A nearby cell tower antenna picks up the signal.
- The signal is passed to a baseband unit (BBU), which cleans it up and gets it ready to send.
- The BBU sends the data to the main network (called the core), which connects it to the internet or another person’s phone.
- The same steps happen in reverse to deliver the signal to the other person.
Figure 1: A depiction of basic RAN architecture
Problems with Traditional RAN:
1. Stuck with One Vendor
- Equipment and software often come from the same company.
- Hard to mix and match parts from different brands.
- Switching vendors is expensive and complicated.
2. Inflexibility
- Hardware and software are built together, so you can’t change one without the other.
- Hard to upgrade just one part or add new features.
3. Expensive
- Equipment costs a lot.
- Big spending needed to build and run the system.
- Takes a long time to buy and install everything.
4. Slow Innovation
- Can’t make changes unless the vendor does.
- Operators can’t try new features on their own.
5. Difficult Maintenance and Upgrades
- Needs special tools and skills from the vendor.
- Upgrades often mean service interruptions.
- Sometimes you need to replace hardware just to update software.
6. Limited Scalability
- Hard to adjust the network for more or fewer users.
- Wastes resources in areas with fewer people.
7. Not Programmable
- Can't customize or control with software.
- No support for automatic updates or smarter control systems.
8. Doesn’t Work Well with the Cloud
- Traditional networks can’t run in the cloud.
- Can’t support modern tech like virtualization or DevOps tools.
9. Hard to Set Up
- Needs lots of physical space and equipment at each location.
- Especially hard to install in rural or remote areas.
10. Takes Too Long to Launch
- Setup takes forever because of all the hardware.
- Delays adding new network features or improvements.
Figure 3: This image shows the necessity for Open Radio Access Networks
Why Open RAN Is Becoming Popular:
Goals of Open RAN
- Make Different Parts Work Together
Use shared standards so equipment and software from different vendors can connect easily. - Break Up the System (Disaggregation)
Keep hardware (like radios) and software (like signal processing) separate so they can be upgraded or changed independently. - Vendor Diversity and Ecosystem Growth
Open the market to more companies, encouraging better prices, faster innovation, and more choices. - Flexible and Fast Networks
Make it easier to build, expand, or change the network quickly based on demand. - Smarter Software Control (Support for SDN & NFV)
Use software tools to manage and automate the network, instead of relying only on physical equipment.
Benefits of Open RAN:
- Reduced Costs
Uses cheaper, off-the-shelf hardware and free/open software to cut costs. - Increased Innovation
Lets network operators pick the best tech from many vendors—not just one. - Faster Rollouts
New features and upgrades can be launched much more quickly. - Improved Automation
Works well with AI and machine learning to help manage the network automatically. - Greater Scalability and Flexibility
Adjusts the network size and resources based on how many people are using it or what services are needed. - Ready for the Future
Built to handle future technologies like 5G, smart devices (IoT),
and whatever comes next
Figure 4: This image shows the goals for Open Radio Access Networks
Heads up!
Terms we will be using for next week:
- RU (Radio Unit): This sends and receives signals (kind of like the ears and mouth of the network).
- DU (Distributed Unit): This processes the signals (like a translator handling all the real-time communication).
- CU (Centralized Unit): This makes big-picture decisions (like the brain of the operation).
Don’t worry if that sounds new since we’ll dive deeper into how each one works in Week 2 and Week 3.
