Research & Development White Paper WHP 368 October 2019 5G RuralFirst: Broadcast Radio Use Case Completion Reports Andrew Murphy, Raj Khokhar, Simon Chirgwin BRITISH BROADCASTING CORPORATION White Paper WHP 368 5G Rural First: Broadcast Radio Use Case Completion Reports Andrew Murphy, Raj Khokhar, Simon Chirgwin Abstract As part of the 5G RuralFirst project, we have been working on a 5G Broadcast Radio trial, testing 4G/5G broadcast to deliver live radio services. The delivery of radio is of particular interest in the context of 5G since radio is a naturally mobile medium and a significant proportion of radio listening is in vehicles and on the move. The project ran from June 2018 until the end of September 2019. This White Paper outlines the work done in the project and the results obtained in the form of BBC inputs to the Use Case completion reports that were written to track contributions to the work of the project. 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White Paper WHP 368 5G Rural First: Broadcast Radio Use Case Reports Andrew Murphy, Raj Khokhar, Simon Chirgwin 1 Overview As part of the 5G RuralFirst project, we have been working on a 5G Broadcast Radio trial, testing 4G/5G broadcast to deliver live radio services. The delivery of radio is of particular interest in the context of 5G since radio is a naturally mobile medium and a significant proportion of listening is in vehicles and on the move. 5G RuralFirst is one of six projects funded under the UK Government’s 5G Phase 1 testbeds and trials programme and aims to demonstrate new approaches to the deployment of connectivity in rural areas, which traditionally suffer from poor coverage and low bandwidth on both fixed and mobile networks. The project targets a number of use-cases ranging from farming and fishing to Internet of Things (IoT) applications. Traditional unicast distribution of broadcast content to mobile devices on 3G and 4G networks has a number of limitations. In urban and suburban areas, unicast is wasteful of resources as multiple copies of the same data are sent to each terminal, which ultimately leads to network congestion and a poor user experience. In rural environments, it is not usually cost effective to deploy a dense network of mobile base stations, so the coverage tends to be uplink limited. As a consequence, the cell sizes supported for unicast delivery are typically smaller than for broadcast delivery using the downlink alone. The aim of the trial was to investigate the role that 5G could have in delivering BBC services to areas that have traditionally been hard to reach and to understand the benefits 5G could bring beyond super-fast connections in densely populated areas. The 5G Broadcast Radio trial comprised two parts; a public trial based on commercially-available 4G equipment and the in-house development of a standalone ‘5G broadcast’ modem that implements the latest mobile broadcast features that won’t be available in commercial handsets until they support 5G. The first phase of the project ran from June 2018 to end of March 2019. An extension to the project, known as Phase 2, was subsequently approved and ran for six months from the beginning of April 2019 until the end of September 2019. The White Paper outlines the work done in the project and the results obtained in the form of BBC inputs to the project Use Case completion reports that were used to track inputs to the project. 2 The First Phase This section details the BBC’s contributions to the Use Case Completion Report submitted at the end of the first phase of the project in March 2019. 2.1 Use of 5G to Broadcast Live Radio Content 2.1.1 Introduction The Internet is becoming increasingly important to deliver the BBC’s programmes and services and it’s important that everyone in the UK can benefit from these even if they live in areas where Internet capacity has typically been limited. Distribution networks have traditionally been application-specific with dedicated networks deployed to deliver fixed TV reception, radio services, 1 emergency service communications or cellular telephony & mobile Internet access. However, 5G offers the possibility of a single family of technology to deliver these different services. Figure 1 – Stronsay location The trial was based on the island of Stronsay in Orkney, an island with a population of around three hundred. This location was chosen in consultation with Orkney Islands Council (OIC) and was picked since it was felt it the technology could bring real benefits to the local people since it currently has almost no mobile coverage, limited fixed broadband capability and limited digital radio coverage. The transmission location was chosen as Stronsay Junior High School, a location which is at the heart of the community both metaphorically and physically. This use case made use of 4G/5G broadcast technology to deliver live radio stations to twenty public trialists who were given a special broadcast-capable Android smartphone. In addition, the participants in the trial benefitted from mobile Internet access for the first time. The aim was to explore whether a more general-purpose infrastructure could be used to deliver radio services and to demonstrate the benefits of combining broadcast delivery for live services with the availability of mobile broadband capability for catch-up services and general Internet use. 2.2 Initial Objectives At the start of the project, we declared a number of specific technical objectives: • Does the technology work? Does it scale? • Switching between broadcast/unicast for efficiency • Broadcast interface aspects between content provider/mobile network and on the handset 2.3 Procurement and Use Case Development In order to try to address the initial objectives, a number of components had to be procured and developed for the trial. Initial predictions for coverage were carried out by the BBC’s Distribution Department and these allowed us to write the specification for the base station transmit power and associated antenna system components. The trial made use of 700 MHz spectrum, 3GPP Band 28. This was chosen due to its good propagation characteristics and the availability of consumer handsets due to the existing use of this band in the Asia Pacific Region. 2 Figure 2 – Initial predicted coverage based on initial transmission parameter assumptions and an omni- directional transmitting antenna The base station (eNodeB) was provided by partner Lime Microsystems based on their software- defined radio platform. The design of the RF components is shown below. Note that two antenna options were specified since, with the omni-directional antenna, the initial predictions suggested that Whitehall Village was on the edge of service. Since it was felt important to provide solid coverage in this location, a directional panel antenna was also obtained to concentrate coverage in this area in the event that there wasn’t sufficient field strength delivered by the omni antenna. Mast-mounted Inside cabinet/building LNA Duplex Cable (pre-amp) filter Downlink Antenna Amplifier Lime SDR LNA Duplex Cable (pre-amp) filter Downlink Target 10m height Amplifier Gaming PC plus AW3464, omni PCI card 1200x296 mm LimeNET 13.5 kg amplifier chassis +6 dBi (2x20W) (2x 90 W EIRP) AW3463, sector 1000x280x120 mm 10.5 kg +12 dBi (2x 317 W EIRP) Figure 3 – RF architecture The conventional unicast network components are supplemented by additional elements to provide the broadcast services, namely a Broadcast Multicast Service Centre (BM-SC) and a MBMS Gateway (MBMS-GW). The resulting network architecture is shown below. Initially a stand-alone core network was used. However, the aspiration is to connect into the 5G RuralFirst core hosted by DataVita. 3 192.168.0.2 IP Power Switch 192.168.0.100 Spectrum Analyser WAN: Backhaul Port 1: eNodeB Port 2: BM-SC Port 3: Power distribution Port 4: Spectrum analyser Amarisoft 192.168.0.77 192.168.0.1 Backhaul Internet eNodeB S1 Asus RT-AC3200 M1 wireless router 192.168.30.77 192.168.30.1 192.168.0.179 MBMS GW BMSC SGmb/ HTTP Content source SGi-mb LimeNET Core PC eBox PC 5GRF Core Stronsay Junior High School Site DataVita Figure 4 – Network architecture including broadcast components The delivery of the broadcast audio is based on MPEG-DASH, a standard that is already used for the BBC’s Internet streaming radio services. It was therefore possible to directly use the BBC’s existing radio feeds to deliver thirteen live radio stations, including BBC Radio Orkney. Figure 5 – The thirteen live BBC radio stations delivered over broadcast in the trial After initial delivery of the base station, a significant amount of collaborative work was carried out with Lime to ensure that the performance of the base station was sufficient.