Offering extensive coverage typically in the range of 6-10 km, the 700 MHz band reduces the requirement of mounting cell towers. This low-latency band can penetrate buildings, unlike higher frequencies that are easily obstructed by objects in their coverage area. These factors make the 700 MHz band an attractive solution for telecom service providers (TSPs) in a geographically diverse country like India.

IR’s rationale for seeking additional spectrum

Since its valuation in 2012, the 700 MHz band has garnered significant attention. Earlier, the Telecom Regulatory Authority of India (TRAI) quadrupled the price of these airwaves compared to that of the 1800 MHz band (valued at Rs 5.54 billion per MHz). Given the precarious financial position of telecom operators, these premium airwaves remained unsold at various auctions until 2022 when Reliance Jio purchased 10 MHz of the 700 MHz band. In the meantime, following TRAI’s recommendations, the 5 MHz spectrum in the 700 MHz band was allotted by the Department of Telecommunications (DOT) to Indian Railways (IR) in 2021. This was done to enhance public safety and security services at stations and in trains.

Recently, IR has urged the assignment of an additional 5 MHz of paired spectrum, free of cost, in the 700 MHz band, citing several key reasons. It maintains that it successfully developed Kavach, its indigenous radio-based train collision avoidance system. As it begins implementing the LTE network in the 700 MHz band, IR will require the additional spectrum for optimising the network’s design. Once IR implements its LTE network and deploys Kavach over LTE, it is willing to surrender frequencies in the 146-174 MHz and 400 MHz bands. Further, it is crucial to capture large-scale data and videos from moving trains in real time, and relying solely on high-capacity stopping stations will not suffice. Moreover, during emergencies, TSPs’ networks often become congested, affecting relief and restoration operations. In its discussions with TRAI, IR stated that it requires a total bandwidth of 13.060 Mbps for download and 45.820 Mbps for upload.

Concomitantly, DoT had sought TRAI’s recommendations on this subject with regard to:

Allocation of 5 MHz of additional spectrum to IR

Spectrum sharing between IR/National Capital Territory Transport Corporation (NCRTC)/regional rapid transit system (RRTS)/metro and other similar networks for greater efficiency

Spectrum valuation methodology and the possibility of uniform spectrum valuation and charging methodology, if needed

Other recommendations deemed fit for the purpose.

TRAI’s recommendations

In July 2024, TRAI issued the “Consultation Paper on Assignment of Additional Spectrum to Indian Railways for its Safety and Security Applications” to solicit stakeholder comments. Eight stakeholders submitted their comments, while three stakeholders provided counter-comments. Based on these views, in December 2024, TRAI finalised the following recommendations. The salient features of these recommendations are…

Assignment of additional spectrum in the 700 MHz band to railways

In response to the July 2024 consultation paper, many stakeholders expressed that IR should be assigned an additional 5 MHz (paired) spectrum in the 700 MHz band considering that IR’s LTE requirements are different from public telecom operators and additional spectrum would be required for network design optimisation. However, other stakeholders stated that since the government has already decided to reserve an additional 5 MHz (paired) spectrum in the 700 MHz band for IR, the deliberation over this issue may no longer be relevant.

In December 2024, the authority recommended alloting 5 MHz of paired spectrum in the 700 MHz band to IR for implementing the European train control system Level 2, Mission Critical-Push-to-Talk (MC PTT) + voice, internet of things-based asset monitoring services, passenger information display systems and live video surveillance feed for two to three coaches at a time. The authority also insisted on ensuring efficient and timely utilisation of frequency spectrum through periodic monitoring.

Further, TRAI stated that to facilitate video surveillance of all coaches in the trains, IR may explore other communication means such as using TSPs’ networks for transmitting constant video surveillance data streams to the control centre or leveraging high capacity Wi-Fi systems at railway stations to transfer video data to the system. IR can also consider implementing AI-based solutions to optimise their requirements due to to limited availability of spectrum in the 700 MHz band.

Lastly, TRAI requested DoT to withdraw the frequency spectrum assigned to IR in other frequency bands, such as the 146-174 MHz bands, 400 MHz band and 900 MHz band, in a time-bound manner.

Spectrum sharing and creation of a common network

Back in 2022, TRAI had recommended that, under DoT’s supervision, the Ministry of Railways conduct a field trial of radio access network (RAN) sharing through a multi-operator core network (MOCN) involving both IR and NCRTC.

Against this backdrop, some stakeholders supported spectrum sharing among rail networks using the MOCN technique in overlapping zones. If the field trial suggested by TRAI in 2022 is successful, it could lead to the optimal use of the scarce spectrum. Additionally, RAN slicing may enable IR and NCRTC to guarantee a defined share of radio network resources. To supplement this, the possibility of spectrum leasing and/or sharing by TSPs can also be examined in the case of capacity crunch.

In its latest recommendations, TRAI maintained its former stance and emphasised that “there ideally should be a common sharable RAN implemented through an MOCN for the operation of different railway networks in the country”. TRAI recommended that DoT take an early decision on its 2022 recommendation on the field trial of RAN sharing through an MOCN. The outcome of this trial can be used to determine the commencement of RAN sharing through MOCNs in the overlapping regions among IR/NCRTC/other RRTS/metro rail networks. TRAI stated that when IR is granted the frequency spectrum, the terms must include a condition requiring IR to implement RAN sharing through MOCNs in overlapping areas with NCRTC/other RRTS/metro rail networks. This will be governed by the guidelines issued by DoT. The regulator stated that until the trial is conducted, if IR uses the 5 MHz paired spectrum assigned to the NCRTC and other RRTS/metro rail networks in some areas, provided the same is not being used in such areas by them, IR may use the band on a payment basis.

Further, one stakeholder suggested that a common network could be constructed by a TSP for rail networks and public land mobile networks (PLMNs), similar to FirstNet in the US. FirstNet is a communication ecosystem revolving around public safety. It was designed exclusively for first responders and those involved in vital efforts such as law enforcement, emergency medical services and fire protection services. If this model is adopted, TSPs could use the network for PLMN services in areas with or without railway tracks (when no train is scheduled). Overall, this would result in optimal spectrum utilisation.

In line with this, TRAI advised DoT to explore the possibility of implementing a common network built by one or more TSPs for rail networks and PLMNs. It emphasised that usage by railway networks must be prioritised over PLMNs.

Need for spectrum harmonisation

TRAI also sought views on the need to harmonise spectrum in the 700 MHz band to make the spectrum assigned to IR, NCRTC and other RRTS/metro rail networks contiguous.

Most stakeholders supported spectrum harmonisation due to various factors. For instance, a contiguous 10 MHz spectrum will have better interference mitigation at loading conditions in overlapping areas. It will also have lower overhead control channel consumption. In contrast, non-contiguous spectrum could impact end-device performance and may not meet IR’s requirements.

TRAI ultimately recommended spectrum harmonisation to be carried out to allot a contiguous block of 10 MHz spectrum in the 700 MHz band to IR and other rail networks with minimal disturbance to the running networks.

Spectrum charging methodology

As per TRAI’s recommendations on the assignment of spectrum to IR, the charges for 5 MHz of paired spectrum are to be paid annually, based on a formula similar to other captive users. For NCRTC, the recommended charges were 0.5 times the auction-determined price (ADP), calculated based on the licensed service area (LSA) and on a pro-rata basis for a 10-year spectrum assignment. In other words, for IR, the spectrum charges are fixed per km, while for NCRTC, they vary across LSAs based on the ADP. As a result, in some areas, the charges borne by IR are greater than NCRTC, and vice-versa.

Stakeholders had differing opinions on this. While some felt that spectrum should be assigned to IR free of cost, a few of them advocated for a uniform charging methodology. Meanwhile, others felt that the charging methodology could not
be uniform.

In the 2024 recommendation paper, TRAI suggested that spectrum charges for IR/NCRTC/other RRTS/metro rail networks must be levied in accordance with the formula for royalty charges and license fees for captive use.

Industry feedback

In a nutshell, the industry has welcomed TRAI’s recommendations on the assignment of additional spectrum to IR for its safety and security applications. The proposed changes are expected to facilitate the optimal use of the scarce spectrum. They were also broadly aligned on the need for spectrum harmonisation. However, stakeholders have also raised concerns, particularly regarding spectrum sharing among rail networks and the spectrum charging methodology.

TRAI has outlined a path forward for DoT, including examining the possibility of implementing a common network built by one or more TSPs, conducting a field trial of RAN sharing through MOCNs, and withdrawing IR’s frequency
spectrum in other frequency bands in a time-bound manner.

Nikhaar Gogna