The beginnings
Access is defined as TDDA and FDDA, both with OFDM modulation. Regarding the user, the UE air interface is defined with Multi-User Multiple Input Multiple Output (MU-MIMO). Another virtue is the implementation of carrier aggregation accesses using a Channel Width (BW) up to 100 MHZ in the DW. Another element such as distributed handover management and closer to the access to be optimised to reduce delay, this gives the lights to Self-Organising Networks (SON) through Software Defined Networking (SDN) and Cloud Network Virtualisation Functions.
We will base our references on the 3GPP TR 25.913 specification, which makes several observations regarding the evolution process leading to the UTRAN towards the E-UTRAN that we will now detail.
Increased RF channel throughput, Carrier Aggregation (CA) facilities are added to MIMO access in the DL that could reach 100 Mbps with a 20MHz channel (5 bps/Hz) and a 50 Mbps UL (2.5 bps/Hz). Today we have several access technologies with performances as shown in Table 1. FDDA/TDDA access supports channelisation with bandwidth capacities of 1.4, 3, 5, 10, 15 and 20 MHz which are summarised in different services as shown in Table 1 and Table 2 RF Channel Performance.
U-plane latency must be less than 5 msec, as delays cause the RF channel throughput to drop exponentially.
In October 2010, the ITU-R WP5D specifications describing the ITU-R M.2012 (IMT-Advanced) recommendations were incorporated, starting REL 10. UE/MS becomes access agnostic, becoming independent of the E-UTRAN/UTRAN medium and starts to share the CN through Packet Data Networks (PDN) as shown in Figure 3. In RELL 11, facilities for positioning-based network support, Continuous Connectivity Service, location information for Multimedia Broadcast/Muticast Service (MBMS) and TDDA/FDDA channel interference management enhancements, CA capability with HeNBs (Home eNBs) and additional CA bands are incorporated:
– LTE-A CA Band 3 and Band 7
– LTE-A CA Band 4 and Band 17
– LTE-A CA Band 4 and Band 13
– LTE-A CA Band 4 and Band 12
– LTE-A CA Band 5 and Band 12
– LTE-A CA Band 20 and Band 7
– LTE-A CA Band 2 and Band 17
– LTE-A CA Band 4 and Band 5
– LTE-A CA Band 5 and Band 17
– LTE-A DL FDD Band 716-728MHz
– LTE E850 Lower Band for Region 2 (not applicable in USA)
With REL 12 in September 2013, the definition of Access Network Discovery and Selection (ANDSF), which allows the use of networks to carry overflow or offloading traffic, such as WLANs (Wi-Fi IEEE 802.11n/ac/ad/aj) and/or WiMAX (IEEE 802.16e) to the EPC, was finally defined in 3GPP TR 23.890.
For data and signalling services from the eNb to the EPC, they are provided via the ‘S1’ interface, where the elements defined in 3GPP TS 23.401 coexist, such as the Mobility Management and Control Entity (MME), with its signalling protocol SCTP [SCTP], controls the mobility plane, mainly for handover. Also the security of access to the E-UTRAN, tracking the UE for subsequent usage reporting. In this case, the MME controller obtains user data from the Home Subscriber Server (HSS) which supports the mobility function, calls and service configuration together with authentication and user level access authorisation. On this same S1 interface, we have the connectivity to the EPC, but at L3 level via IP protocol with the Service Gateway (S-GW), which performs the IP connectivity between the UE/MS and the Packet Data Network Gateway (PDN GW) which is the border between the EPC and external IP networks (Internet). The subscription of an MS/UE is validated by the Public Land Mobile Network (PLMN) through the process of establishing IP Connectivity Network Access (IP-CAN) for HSS, as defined in 3GPP TS 23.060 [3], 3GPP TS 23.401 [77] and 3GPP TS 23.402 [78].
Another feature is the creation of UE hosting to eNB (or HeNB) units, which allows delivering IP connectivity locally and maintaining connectivity to the HSS, thus delivering network services to the UE even though it has a routing plan associated to the Local network as shown in Figure 4.
In REL 14 new functions and enhancements are added as follows
Examples of enhancements in RAT scope
Enhancements Proximity Service Assignments (13, 14)
Internet of Things RATs (NB-IoT, enhanced LTE, EC-GSM-IoT)
LTE-A CA access enhancements(13, 14)
Support for LTE sidelink-based Vehicle-to-Vehicle Services(14)
Promotes launch of LTE and eMBMS (13, 14)
Examples of System Level Enhancements
Enhanced Cellular Systems for IoT (13)
Dedicated CN (13) and Dedicated eCN (14)
Separation of Control Plane and User Plane (14)
Support for Virtualisation Functions (VNF) in terms of Operation and Maintenance (O&M) (14)
Support for Broadband (BB) Mission Critical applications – Mission – Video and Data (14)
Figure 4 – Connectivity with UMTS/LTE cell-hosted LTE-A eNB (REF 3GPP ts_36300)
Commercial evolution
Existing commercial evolution is described
Commercial requirements sets completed June 2018 /REL15 (eMBB)
July 2020/REL16 for IMT 2020, define use cases and customer requirements (Massive IoT, URLCC, V2V).
We will base our reference on the scenarios set out in 3GPP TR 38.913 and in ITU-R M.2410 reports by IMT-2020, regarding Radio Interface Technology (RAT) performance enhancement techniques to incorporate Enhanced Mobile Broadband Access (eMBB), facilities are created for Massive Machine Communication Types (mMTC), mainly to serve telemetry and telecontrol type service (IoT Internet to thing) and Ultra-Reliable and Low Latency Communications (URLLC) defined according to 3GPP TR 22862.
New Radio Technologies (NR) are incorporated, such as Small Cell Network (SCN) and LPN Low power node, focused on optimising the use of infrastructure.
- Incorporation of 3D-Beam Focused (3D-BF) technologies.
- Active Antenna Systems (AAS)
- Massive MIMO
- The model shall be based on synchronism in space, time and frequency.
- Support extended channels up to 10% of their carrier frequency.
- Vehicle Speed [500] km/h.
TDD-FDD joint operation, dual connectivity and dynamic TDD can also improve spectrum flexibility. Table 2 of Performance Evolution from REL 9 to REL 15 is attached.
- 4G LTE LTE-A 5G Technology REL 15 5G mmW
- Spectrum 2600 Mhz 2600/1900/ 700 Mhz 3500 Mhz 24-28 Ghz
- BW 20 MHz 50 MHz 100 MHz 100 Mhz 800 MHz
- Maximum Speed 150 Mbps 600 Mbps 2 Gbps 20 Gbps
- RAT Efficiency 2 bps/Hz 2 bps/Hz 3-12 bps/Hz 3-12 bps/Hz 3-12 bps/Hz
- Services Rate 40 Mbps 100 Mbps 0.25-1 Gbps 2-10 Gbps
Network technologies
Future IMTs will require more flexible network nodes, which are configurable according to software-defined networking (SDN) architecture and network functions virtualisation (NFV) in order to achieve optimal processing in the node functions and improve the operational efficiency of the network.
Through centralised and collaborative system operation, the Cloud RAN (C-RAN) aggregates baseband and higher layer processing resources to form a pool, so that these resources can be dynamically managed and allocated on demand, while radio units and antennas are deployed in a distributed manner.
The radio access network (RAN) architecture must support a wide variety of options for the types of inter-cell coordination. Advanced self-organising network (SON) technology is an example of a solution that allows operators to improve the OPEX efficiency of the multi-RAT and multi-layer network, while meeting the increasing throughput requirements of the subscriber.
SDN, NFV and C-RAN: characteristics
Saving bandwidth and improving transmission efficiency is the trend in evolutionary multimedia broadcast and multicast service (eMBMS). Dynamic switching between unicast and multicast transmission can have its advantages.
Report ITU-R M.2376 explains the technical feasibility of IMT at frequencies between 6 and 100 GHz. It includes information on possible new radio systems and technologies for IMT, suitable for operation in this frequency range.
The Report describes solutions based on MIMO and beamforming with numerous antenna components, which compensate for the increasing propagation loss with frequency; these solutions are becoming increasingly feasible through the exploitation of integrated circuit scale antenna solutions and adaptive modular antenna arrangements that do not require ADC/DACs in each antenna component. The feasibility of manufacturing commercial transmitters and receivers operating at these frequencies is being investigated, as demonstrated by the availability of commercial 60 GHz multi-gigabit wireless systems (MGWS) and the prototype activities that have already started at frequencies such as 11, 15, 28, 44, 70 and 80 GHz.
Radio Technology (RT) requirements for Vehicle-to-Vehicle Mobility (V2X) communication are incorporated in the 3GPP TSG-SA WG1 Meeting #76-bis S1-170313, detailing requirements associated with delays of less than 10 sec between a group of UE supporting V2X applications, 25 msec in other applications and only 30 msec for brodacast applications supporting V2X and with respect to availability to be supported over [99.99] % within a range of 80 metres from the nearest ARP.
RATs are incorporated in licensed bands in 5.8 Ghz where 120 Mhz of spectrum is available for LTE-U, according to 3GPP RP-151606. Additional RATs are incorporated for bands above 100 Mhz. The impact of UEs on the E-UTRAN shall be minimised by supporting only 5G RAT(s) based on V2X communication, for which V2K Multi Channel systems are under development. We also have support for technologies capable of massively managing elements as described in 3GPP TR 22.824 (MIoT).
It also incorporates new NR management tools for monitoring in conjunction with planning and enhancements to the RAT plane (SRAT) and adds support for Virtual Private Network (VPN) services, as described in the 3GPP TR 22.821 technical specifications.
Finally, it is understood that such a deployment cannot be realised without coordinating entities at both public and private level to meet the defined requirements. Some initiatives that are planned today, is the European Partnership5G PPP (5G Infrastructure Public Private Partner ship) working between the European Commission and the Telecommunications Operators Manufacturing Industry (ICT), Service Operators Institutions and Partnerships that set 21 Infrastructure projects launched in Brussels in June 2017.
