Open source plays a very crucial part in the world of technology. Every piece of technology today is either fundamentally dependent on it to leverage its growth or to become completely operational. Let us see how it fares with the development of the 5G testbed.
The open source effort to establish a 5G testbed is part of a project that was founded by the Department of Telecommunications of the government of India. It has been running for about four years now. There were nine principal investigators on this project.
The project itself officially ended on 1st January 2022. Now, at the Indian Institute of Science in Bengaluru we are on to the maintenance of the project where we maintain the testbed and encourage its usage and do minor developments.
The following is the overview of different aspects of what this project is all about. There are fundamentally four parts to it. Let us dive in and understand about these attributes.
1. System development in sub 6GHz (FR1)
The 6-gigahertz (GHz) development platform is the portion that is actually open source. We have primarily looked at physical layer enhancements and implemented the split six architecture, also called algorithms, and integration with different radio units. We have developed antenna arrays 16 by 4 that are 6499 arrays with an up-down converter and transceiver for the sake of completeness, while testing it alongside extensively in an antiquated chamber.
2. Vehicle-to-X (V2X) platform
It is a Long Term Evolution (LTE) based platform. It is a fully functional platform, which can perform end-to-end latency measurements. We have enhanced the MAC schedulers in LTE and reduced the latency of a native implementation of LTE by a factor between 5 and 10. Also, the remote driving capabilities have been demonstrated on campus.
3. Visible light communications (VLC) system development
This is a complementary technology to 5G and not a mainstream one. We have built a communication system which is able to deliver about 4.8 gigabytes per second using OFDM. It also incorporates beam steering and has technical knowledge to create its backbone.
4. Features of Sub-6 system
We are using a generic radio platform based on the universal serial radio port. This can be operated anywhere up to 6GHz but is primarily focused on the 3.3GHz to 3.8GHz frequency band. The other features are all supported by our testbed, including 30kHz carrier spacing. It has around 100MHz bandwidth and up to 256 QAM. The value proposition of this testbed is that it is a fully open sourced platform, so every part of the 5G radio stack is available to be modified. It has been well tested with USRP X310 and B210 radios as well as with commercial phones like the OnePlus 9 Pro 5G and Oppo A74.
Lab system: connection model
Essentially, we have USRP radios that are connected to a personal computer (PC) where the gNB1 software stack will be running in a monolithic implementation. Then they are connected over the network as well.
We have tested it with two different types of cores as well, namely, OpenAirInterface (OAI) 5G core and the Open 5GS core. These cores run on different systems.
The USRPs (refer Fig. 1) act as gNB base stations and can be connected to either user’s equipment software. It could connect to another USRP and also to another 5G phone.
Experiments performed so far
We have conducted multiple experiments that include hands-on experiments with the RAN. We have looked at the impact of different parameter settings. We have also looked at different types of real and simulated systems with different types of antennas and how that affects the connectivity and the data rates thus procured.
Core network allows us to analyse various entities and understand the configuration of AMF, SMF, UPF, etc. It also allows us to verify the sequence of events logged at gNodeB and CN. It provides us with a better understanding of SIM card functions.
TSDSI interaction and work in progress
The vision of TSDSI is to ensure that digital communication standards increasingly drive domestic, economic, and policy activities and enhance India’s competitiveness for ICT goods and services in global markets. It aims to do this by creating a leadership position through India’s participation and contribution to emerging digital communication standards in global SDOs.
Recently, TSDSI SGI Standard & NaviC (Satellite based Indian Navigation System) have become part of 3GPP. The CPRI Fronthaul Transport standard developed by TSDSI has been taken up by TEC for adoption as a National Standard. Open source begins where standardisation efforts end. They both work hand in hand and can not only co-exist but also augment each other.
|5G Hackathon India|
We contributed to the 5G Hackathon India where our three entries were selected among top 100 out of about 1500 entries:
TSDSI role in open source
TSDSI has also established an open source task force to study and evaluate open source components required for building an end-to-end system. It explored how open source projects can accelerate the Indian 5G ecosystem. Weekly meetings were conducted for over nine months with broad industry as well as academic participation. The findings were published in August 2021. Some potential impacts are:
- It is a game changer for original equipment manufacturers (OEMs) and service providers.
- Expedites SGI for rural India.
- It reduces the cost of implementation by about 50-60%.
- Comprehensive, well tested open source platform with support.
Building such an open source platform, which can actually reduce the development cost for OEMs, allows project developers to focus on their core competence. We want to keep our approach similar to that of the Red Hat model. There will be basic software available for free and you will have to pay in order to avail more services.
The overall idea is to have three pillars on which this will be built:
- Technical leadership from academia with well-experienced faculty from academia who have experience with several successful projects.
- Dedicated core development team consisting of a team with prior industry experience.
- A strong industry participation through volunteerism to take on specific sub projects and projects of interest.
IOS – 5G scope
So, in simple terms, there are just two deliverables which we are aiming at. The first one is the DU/CU and the second is the core 5G part of the network. The second part is going to be the RAM intelligent controller (RIC) and the service management orchestration in a cloud based deployment.
In the end, it is important to note that the 5G testbed is open for people to use. In order to use the testbed you can visit 5Gtestbed.in where all the currently offered services can be found. One just has to register their company and then they can start using the testbed.
This article is put together from a tech talk session by Dr Chandra R. Murthy of the Indian Institute of Science at Open Source Conference 2022: Proliferation of Open Source for Emerging Technologies, organised by Samsung R&D Institute India – Bangalore and IEEE ComSoc Bangalore Chapter. It has been transcribed and curated by Laveesh Kocher, a tech enthusiast at EFY with a knack for open source exploration and research.
Dr Chandra R. Murthy is a Professor in the Department of Electrical Communication Engineering at the Indian Institute of Science, Bengaluru