## 1 Introduction  
The proliferation of cellular communications and, more categorically, the evolution of 5G, has become an essential part of the community. Firstly, as an enabler for more expeditious communication channels, widening the scope of offered accommodations; and secondly, by ascertaining communication reliability across various heterogenous sectors [1]. The stringent requirements of First Responder (FR) teams for reliable and ubiquitous communications, and low latency for authentic-time applications, have been consummated by vendor-driven proprietary technologies with a constrained interoperability and narrow space for innovative accommodations. 5G has the objective to exploit one technology to accommodate all accommodations and application requisites. Thus, it seems to be congruous for a shift in the deployment of future First Responders' accommodations and handling of crisis situations, offering swift communications infrastructure deployment, reliability, and low latency. Consequently, evolving 5G communications are destined to play a vital role in crisis situations for the accommodation of accommodations beyond audio communications such as AR, precise tracking, monitoring, etc., incrementing the operational potential. Difficulties in efficient communication through cellular networks are conventionally presented due to congestion in flash crowd events, or damaged infrastructure due to natural disasters. Consequently, accommodation assurance in emergency communications for First Responders is a crucial factor for efficiency in a variety of emergency operations, such as weather hazards, geophysical hazards, and technological hazards. Aimed at addressing concurrent multiple requisites emanating from different accommodations and operational objectives, the network slicing paradigm was introduced by 5G, sanctioning network operators and carriers to split the resources of physical or virtualized infrastructure, and assign them to different applications/tenants with predetermined criteria. More concretely, 3 GPP standards define three accommodation slice types (SST), predicated on the underlying services' requisites and demands [2; 3]. These are broadly known as: (i) Enhanced Mobile Broadband (eMBB), which addresses the high bandwidth use cases for access to multi-media content, accommodations, and data. ; (ii) Ultra-reliable and low latency communications (uRLLC): this network slice type sets stringent requisites for key performance designators such as throughput, latency, and reliability. Some examples for emergency communications include UAV control, remote assistance, conveyance safety, etc. ; (iii) Massive machine-type communications (mMTC): the latter network slice type is characterized by the ability to accommodate many connected devices, which transmit data with low bandwidth and low delay tolerance. With reference to FRs' requirements, it provides the enhanced operation for multiple communication devices and sensor aggregation [4], commonly required when many FRs are deployed in the area of an incident. In this paper, the H2020 RESPOND-A project approach is presented, as a 5G enabled platform for First Responders. The EC-funded project focuses on, among others, the integration of various technologies utilized in the field by several responder groups, and how their accompanying accommodations can be enhanced by utilizing 5G network slicing. The key aspect of the RESPOND-A approach is the introduction of the Portable Communication System (PCS), which facilitates responder teams per each emergency scenario on-site, by providing not only 5G connectivity at the incident area, but also advanced accommodation management and resource management for FR accommodation deployment. Each accommodation has different requirements and designations which, under stringent emergency conditions, need to be explicitly addressed.