The fifth-generation (5G) wireless networks will be able to sustain a diverse variety of applications, ranging from high-speed broadband services (e.g., virtual and augmented reality) to ultra-reliable low-latency services (e.g., disaster search and rescue networks), to massive internet of things (IoT) services. 

In this regard, millimeter-wave (mm-wave) communications (using above 6GHz transmit frequencies) is envisaged to be an integral part of the 5G ecosystem. In particular, due to the large bandwidth available at the mm-wave spectrum, 5G target broadband data-rates of 1 Gbps seem feasible. However, transmissions at such high frequencies suffer from detrimental propagation losses and sensitivity to blockages. As an example, whenever the mm-wave transmission is obstructed by an object like a vehicle, human, or buildings, the mobile user can experience service outage (equivalent to losing all network bars in the mobile phone). These issues pose significant engineering and network-design challenges, and open questions such as: how to provide indoor coverage using mm-wave access-points (or small cells)? How to extend the outdoor coverage of such mm-wave access points? Can the mm-wave access points operate reliably without using the existing 4G LTE architecture?

The wireless communications research group in IIIT Delhi is investigating these challenges. In particular, the researchers have developed protocols for mm-wave augmented positioning using relays for disaster-relief scenarios [1], service-aware mm-wave provisioning schemes for cellular users [2], and coverage enhancement for indoor mm-wave systems [3]. Their results provide several key system-design insights for the network operators aiming to deploy 5G mm-wave systems.

Currently, they are developing intelligent algorithms to facilitate multi-connectivity, agile band-switching, and robust blockage-aware protocols to improve the reliability of mm-wave cellular and ad-hoc networks.

The papers (accepted recently this year are):

[1] G. Ghatak, A. De Domenico and M. Coupechoux, “Relay Placement for Reliable Ranging in Cooperative mm-Wave Systems,” in IEEE Wireless Communications Letters, vol. 8, no. 5, pp. 1324-1327, Oct. 2019. DOI: 10.1109/LWC.2019.2915824

[2] G. Ghatak, A. De Domenico and M. Coupechoux, “Small Cell Deployment Along Roads: Coverage Analysis and Slice-Aware RAT Selection,” in IEEE Transactions on Communications, vol. 67, no. 8, pp. 5875-5891, Aug. 2019. DOI: 10.1109/TCOMM.2019.2916794

[3] G. Ghatak, Coverage Enhancement in Indoor Millimeter WaveSystems Under Random Human Blockages, in IEEE International Conference on Advanced Networks and Telecommunications Systems 2019 (Accepted)