Month: July 2017

Jose F. Monserrat (Universitat Politècnica de València)

Last week, on June the 21st 2017, ITU-R WP5D Niagara Falls meeting concluded with little advances, but at least a clear definition of the agenda to standardize IMT-2020 Radio Interface Technologies, the 5G. Even being the radio community eager to say that 5G is just around the corner, the 5G label will be provided by ITU-R by October 2020, likely more than two years after the first “5G” networks will be deployed.

The full process includes the following milestones:

• March 2016: the invitation to propose Radio Interface Technologies (RITs) was released.
• July 2019: deadline for the reception of candidate proposals.
• February 2020: all evaluation reports from external evaluation groups must be received.
• June 2020: ITU-R will provide the  key characteristics of 5G technologies.
• October 2020: ITU-R will finish the RIT specification recommendations.

In the meantime, what is also under way is the technological evaluation of the candidate technologies. As in previous generations, candidate radio access technologies will be proposed and a set of institutions and research centers will carry out a comprehensive evaluation to see if the candidates are able or not to meet the requirements set by the ITU-R for this mobile generation. For the 5G, the requirements are still under discussion, although good hints are available already in draft form [1]. The steps in the whole procedure are described in the figure below.

Figure 1. Detailed procedure of the IMT-2020 evaluation [2].

With respect to the simulation of the 5G candidates, ITU-R is currently working in a document, the ITU-R M.[IMT-2020.EVAL] report, to be released by November this year, in which all details for simulations will be included. Evaluations will be performed in strict compliance with the technical parameters provided by the proponents and the evaluation configurations specified for the test environments in this IMT-2020.EVAL report. What we already know (there is a draft version since June 2017) is the set of Key Performance Indicators (KPI) to be evaluated and some details on the test environments and network layout for simulations. As one of the most interesting novelties, there will be two new environments, as compared with the IMT-Advanced process, in an urban macrocellular deployment:

• Urban Macro–mMTC: an urban macro environment targeting continuous coverage focusing on a high number of connected machine type devices.
• Urban Macro–URLLC: an urban macro environment targeting ultra reliable and low latency communications.

The second one is likely to focus on Vehicle-to-Vehicle (V2V) communications, since this seems to be the most significant service that will define the 5G [3]. The characteristics of the propagation models that will be used for the modeling of this V2V communication and how the shadowing effects in this type of communication will be taken into account are still to be seen. The right modelling of these two aspects is fundamental to have an accurate assessment on the performance of the RIT candidates [4][5], so it is requiring long discussions within the WP 5D.

The following principles are to be followed when evaluating RIT for IMT‑2020:

• Evaluations of proposals can be through simulation, analytical and inspection procedures.
• Evaluations through simulations contain both system-level and link-level simulations. Independent evaluation groups may use their own simulation tools for the evaluation.
• In case of evaluation through analysis, the evaluation is to be based on calculations which use the technical information provided by the proponent.
• In case of evaluation through inspection the evaluation is to be based on statements in the proposal.

The IMT-2020 submission and evaluation process is is guided by Resolution ITU-R 65. At this point in time, interested groups can still apply to become external evaluators of the RIT IMT-2020 candidates. So far the following groups have been accepted:

• 5G Infrastructure Association
• ATIS WTSC IMT-2020 Evaluation Group
• ChEG Chinese Evaluation Group
• Canadian Evaluation Group
• Wireless World Research Forum
• Telecom Centres of Excellence, India
• The Fifth Generation Mobile Communications Promotion Forum, Japan
• TTA 5G Technology Evaluation Special Project Group

Now the main question is whether there will be more than one candidate technology or not…

References

[1] ITU-R SG05 Contribution 40, “Draft new Report ITU-R M.[IMT-2020.TECH PERF REQ] – Minimum requirements related to technical performance for IMT-2020 radio interface(s)”, February 2017.

[2] ITU-R IMT.2020 Contribution 2, “Submission, evaluation process and consensus building for IMT-2020”, June 2016.

[3] Calabuig, Jordi; Monserrat, Jose F; Gozalvez, David; Klemp, Oliver; “Safety on the roads: LTE alternatives for sending ITS messages”, IEEE Vehicular Technology Magazine, vol. 9, no. 4, pp. 61-70, 2014.

[4] Monserrat, JF; Fraile, R; Rubio, L; “Application of alternating projection method to ensure feasibility of shadowing cross-correlation models”, Electronics Letters, vol. 43, no. 13, 2007.

[5] Monserrat, J; Fraile, R; Cardona, N; Gozalvez, J; “Effect of shadowing correlation modeling on the system level performance of adaptive radio resource management techniques”, Wireless Communication Systems, 2005. 2nd International Symposium on, 2005.

[6] IMT-2020 submission and evaluation process webpage. https://www.itu.int/en/ITU-R/study-groups/rsg5/rwp5d/imt-2020/Pages/submission-eval.aspx

 

Ki Won Sung (KTH Royal Institute of Technology)

5G systems are expected to provide a wide range of services including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Providing the enhanced and new services would require more frequency spectrum to be used for 5G. Furthermore, the characteristics of each service may fit to different frequency bands ranging from low to high bands, e.g., from sub-1GHz up to 100 GHz. Therefore, it is important to identify the frequency bands both available and suitable for 5G systems.

In the international level, the most important decisions on the spectrum allocation are made in World Radiocommunication Conference (WRC) which is organized by International Telecommunication Union (ITU) in every four years. The latest WRC was held in 2015 (WRC-15), and the next one will be in 2019 (WRC-19).  In WRC-15, an agreement was made on a WRC-19 Agenda Item (1.13) to consider the identification of frequency bands for the future development of International Mobile Telecommunications (IMT), which includes possible additional allocations to the mobile service on a primary basis, in accordance with Resolution 238 (WRC-15). It entails the appropriate sharing and compatibility studies for a number of bands between 24-86 GHz in time for WRC-19. The details of the frequency bands for studies can be found in Figure 1 [1].

Figure 1: Frequency bands for studies for IMT in ITU-R until WRC-19 [1].

Apart from the higher frequency bands studied for WRC-19, parts of frequency bands around 3400-3800 MHz have obtained interest in various regions of the world. In Europe, the entire band of 3400-3800 MHz is harmonized for mobile/fixed communications networks (MFCN) according to an ECC decision [2]. The Radio Spectrum Policy Group (RSPG) considers 3400-3800 MHz to be the primary band for the introduction of 5G services provided that the frequency band is already harmonized and it offers wide channel bandwidth of 100 MHz or more [3]. In Japan, Ministry of Internal Affairs and Communications published the national report “Radio Policies Towards 2020s”, which selected 3.6-4.2 GHz, amongst others, as national candidate for 5G [4]. China also studies the availability of 3.3-3.4 GHz, and has announced a 5G trial in the 3.4-3.6 GHz band [4]. In the USA, Federal Communications Committee (FCC) has established Citizens Broadband Radio Service (CBRS) in the 3550-3700 MHz on a shared and technology-neutral basis. CBRS employs a three-tiered spectrum authorization framework to accommodate a variety of incumbent federal and commercial non-federal users on a shared basis. Specifically, it has three hierarchies of spectrum users: incumbent access, priority access, and general authorized access [5]. In addition to the 3550-3700 MHz, the “Mobile Now” Act proposes further studies on 3100-3550 MHz and 3700-4200 MHz that could offer additional 500 MHz bandwidth in the 3.5 GHz range [6].

 

References

[1] ICT-671680 METIS-II, Deliverable D3.2 Version 1, “Enablers to secure sufficient access to adequate spectrum for 5G”, June 2017.

[2] ECC/DEC/(11)06, “Harmonised frequency arrangements for MFCN operating in the bands 3400-3600 MHz/3600-3800 MHz”, December 2011.

[3] RADIO SPECTRUM POLICY GROUP Opinion on spectrum related aspects for next-generation wireless systems (5G), “STRATEGIC ROADMAP TOWARDS 5G FOR EUROPE”, November 2016.

[4] A GSA Executive Report from Ericsson, Intel, Huawei, Nokia and Qualcomm, “The case for new 5G spectrum”, November 2016.

[5] US Federal Communications Commission (FCC), “Amendment of the Commission’s Rules with Regard to Commercial Operations in the 3550-3650 MHz Band”, April 2015.

[6] https://www.congress.gov/bill/115th-congress/senate-bill/19, March 2017.