Public Protection and Disaster Relief (PPDR) networks cater to communication used by agencies responsible for both public protection (maintenance of law and order, protection of life and property) and disaster relief for dealing with serious disruptions to the functioning of society that pose a significant threat to human life, health, property or the environment. PPDR networks should support voice services enabling features of push-to-talk, point-to-multipoint communication, group calling, caller identification, emergency alert and high audio quality. Today, PPDR agencies use information from a variety of databases, geographic information systems, video imagery, etc, which require transmission of data. Depending on the type of data, the speed requirements for transmission vary. For example, sending a fax would require narrowband (up to 64kbps), transfer of images and videos would require wideband (384-500kbps), and remote control of robotic devices such as in case of bomb retrieval robots, imaging/video robots or even live video requires broadband (1-100Mbps). One can envisage the benefits of having knowledge of the terrain in case of flood relief operations through high quality images and video, non-human intervention in life threatening scenarios through robotics, M2M and IoT. This knowledge and capability requires high speed data transmission and helps in making PPDR operations more effective and efficient. Thus, the need for PPDR networks that support higher data rates, along with video and multimedia capability—in addition to voice applications that can enhance situational awareness and resource allocation—is ever increasing.
Interoperability between networks enhancing cooperation and effectiveness of measures and low cost of deployment are also important considerations for PPDR networks. Notwithstanding the need for such networks to have high availability, with sufficient capacity and redundancy to handle peak traffic, extensive coverage to even cover operations in most remote areas is critical. Mobility features to serve in most vigorous environments, good QoS for voice and data services, secure and highly reliable mobile broadband network is essential. Prevalent technologies being utilised for mobile PPDR networks have voice and text service related features integrated, whilst data services range between narrowband to wideband. With the need for high speed PPDR networks supporting broadband data services, ITU has detailed the advantages of LTE deployment for PPDR. In the latest LTE releases, the technology has been updated to support some of the features required for PPDR networks (mission critical communications). With LTE technology still evolving and features like group communications and pre-emptive services yet to be introduced, it would take time to make all features for public safety (voice and data communications) available in commercially available LTE equipment. Hence, we could be seeing legacy PPDR networks continuing to coexist with LTE providing broadband capability. In India, most PPDR agencies operate their own independent voice-oriented networks on a variety of frequency bands and technologies, mostly trunked radio services. If one needs to evaluate whether PSUs should be earmarked for providing nationwide broadband PPDR communication network, the effective network strategy deployment model could be a shared commercial network or a hybrid network infrastructure model. In both the network strategy models, PSUs would be providing their LTE network for broadband data services and enhanced coverage in terms of mobility and capability. In India, PSUs are yet to embark on the LTE journey, with broadband being provided by GSM 3G, CDMA EVDO and WiMAX. Considering the costs associated with building a resilient, redundant and highly available LTE network, this would require thorough planning and dedicated capex allocation to the PSUs selected. Further, considering the importance of timely deployment, efficient project management would be critical. With reliability and security being key requirements for PPDR networks, the network model could benefit for extensive infra and networks deployed by the PSUs which are already servicing government agencies.
Operators with LTE capability need to consider the additional cost burden for implementing mission-critical features in their LTE equipment. Also, PPDR communications on LTE networks would require allocation of additional spectrum (most developed countries have dedicated spectrum for PPDR) to provide the reliability and quality expected. Globally, various models have been deployed, such as ‘commercial network with hosted public services model’ where existing mobile broadband providers have been used for deployment of PPDR networks, over which PPDR applications and services of PPDR agencies are hosted. There are examples of ‘public safety over mobile broadband provider’ through a government established entity providing the core network enabling broadband services and connecting radio networks of PPDR agencies existing in states. There is no one-size-fits-all approach, and building pan-India PPDR networks would require implementing a network model that is both cost-effective and quick to deploy. India could adopt a hybrid RAN sharing model, with PSUs housing the core network enabling broadband capability and integrating all PPDR agencies, whilst utilising RAN sharing model with private commercial players to reduce the time to market and lead time in deployment of pan-India LTE radio network. PSU involvement should be a function of chosen network deployment strategy, availability of existing telecom infrastructure, spectrum allocation plan, PPDR agency networks and gaps, costs involved and timelines for deployment, amongst other factors. The involvement should be based on value that would be delivered in deploying an effective and efficient next generation, or simply put, broadband PPDR network for India.