5G enables enhanced services and business models. 3GPP continues to define specifications of 5G. 3GPP aims to complete 5G Phase 1 as part of Release 15 in September 2018 and 5G Phase 2 as part of Release 16 in December 2019 [3GPP_Plan]. 5G Phase 1 defines (i) New Radio (NR)-based air interface with features, such as flexible and more efficient OFDM, scalable frame structure, massive MIMO and advanced coding techniques, (ii) new decomposed radio network architecture, (iii) new serviced-based, virtualization-oriented, and modularized 5G core network, and (iv) frameworks, such as network slicing and Multi-access Edge Computing (MEC). These 5G features enable a variety of usage scenarios, such as enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine Type Communications (mMTC). Candidate technologies for 5G Phase 2 include Integrated Access and Backhaul (IAB), 5G New Radio (NR)-based Enhanced Vehicle-to-Everything (eV2X), NR-based use of unlicensed spectrum, Non-Orthogonal Multiple Access (NOMA) and non-terrestrial systems. New service classes, such as Ultra High Speed Low Latency Communications (UHSLLC) could very well emerge in Phase 2 and beyond. Let’s take a quick look at these 5G Phase 2 technologies.
Integrated Access and Backhaul (IAB). IAB shares a given wireless channel between the access link (i.e., the link between the wireless device and the base station) and the backhaul link (i.e., the base station core network link or base station link for relays). Wireless backhaul reduces the cost reduction of deploying NR by avoiding expensive fiber-based backhaul. Wireless backhaul incorporates features, such as topology management, route optimization and dynamic resource allocation between backhaul and access, and aims for high spectral efficiency and high reliability [IAB]. IAB becomes more attractive at mmW bands due to the availability of the large amount of spectrum.
Enhanced Vehicle-to-Vehicle Everything (eV2X). 5G NR can be used for eV2X uses cases [eV2X]. Examples of eV2X use cases include vehicle platooning, sensor and state map sharing, remote driving, automated cooperative driving, and collective perception of environment. Vehicle platooning means that a group of vehicles is operating together (e.g., like a train with virtual strings attached between vehicles [eV2X]). Platooning enables the reduction in the distance between the vehicles for faster traffic movement and reduces the fuel consumption. Sensor and state map sharing involves the sharing of sensor data to create collective situational awareness to facilitate vehicle platooning, intersection safety, and emergency vehicle communication. Remote driving means that a vehicle is controlled remotely by either a human operator or cloud computing using feedback, such as video camera streams. Remote driving can be much less complex than autonomous driving and can be used for use cases, such as buses following specific routes. Automated cooperative driving involves automatic communications among a group of vehicles for lane changing, merging and passing for enhanced safety and fuel economy, and reduced greenhouse gas emissions. Collective Perception of Environment (CPE) involves the exchange of real-time information related to sensors and roadside units to avoid accidents.
NR-Unlicensed (NR-U). 3GPP extends the concept of Licensed-Assisted Access (LAA) from LTE to 5G NR, where a licensed carrier is used as the anchor and that anchor is aggregated with multiple unlicensed (and licensed) carriers to significantly increase throughput via parallel transmission of user traffic. The goal is that the NR-based operation in the unlicensed spectrum should not impact deployed Wi-Fi networks more than an additional Wi-Fi network on the same carrier. Example unlicensed spectrum frequency bands being evaluated include 2.4 GHz, 3.5 GHz, 5 GHz , 6 GHz, 37 GHz, and 60 GHz bands [3GPP_NR-U]. Some of these bands are available globally, while others are only available in specific regions. Potential deployment scenarios include (i) carrier aggregation between licensed band NR and NR-U (ii) dual connectivity between licensed band LTE and NR-U, (iii) standalone NR-U, (iv) NR cell with DL in unlicensed band and UL in licensed band, and (v) dual connectivity between licensed band NR and NR-U.
Non-Orthogonal Multiple Access (NOMA). The industry is exploring an alternative to OFDMA to further increase spectral efficiency. Non-Orthogonal Multiple Access (NOMA) involves the use of overlapping subcarriers in a cell for different users to make more radio resources available and thereby increase overall capacity and throughput. Successive Interference Cancellation (SIC) is implemented at the receivers. Different transmit power levels and different codes can be used for the users using NOMA. Example techniques include Resource Spread Multiple Access (RSMA) and Sparse Code Multiple Access (SCMA) [NOMA].
Non-Terrestrial Systems. In addition to traditional cellular networks, 5G can be applied to non-terrestrial networks, such as satellite networks. Example benefits of non-terrestrial networks include wide service coverage and reduced vulnerability of space or airborne systems to physical attacks, as well as natural disasters. Hence, non-terrestrial networks can facilitate cost-effective deployment of 5G services in un-served areas (e.g., isolated or remote areas, aircrafts and marine vessels) and underserved areas (e.g., rural areas). Non-terrestrial networks ensure seamless and reliable 5G services by providing service continuity for moving IoT devices or people (e.g., aircraft and ships). Non-terrestrial networks can operate or in conjunction with terrestrial networks. Example verticals for non-terrestrial networks include transport, public safety, media and entertainment, eHealth, energy, agriculture, finance, and automotive.
While 3GPP is finalizing 5G Phase 1, it is also evaluating several technologies for 5G Phase 2. These candidate technologies, such as IAB, eV2X, NR-U, NOMA, and non-terrestrial networks, would further expand 5G to even more industries and deployment scenarios compared to 5G Phase 1.
About the Authors
Dr. Nishith Tripathi is 5G Prime for Award Solutions. Nishith joined Award Solutions in 2004, and has over 20 years of experience in telecom. Nishith has brought his knowledge and experience in mobile wireless technologies to facilitate the planning, development and delivery of technical training.
Khyati Tripathi is a Senior Consultant for Award Solutions. Khyati is an experienced and accomplished Telecommunications Technical Project Manager of software development projects consisting software development cycle of traditional (waterfall) and agile (scrum) methodologies.
About Award Solutions, Inc.
Award Solutions is the trusted training partner to the world's best networks. We help companies tackle new technologies by equipping their teams with knowledge and skills. Award Solutions invests heavily in technology, research, engineering, and labs to ensure our customers make the most of their resource and network investments.
Award has expertise across all technologies that touch wireless: 5G, Artificial Intelligence, Machine Learning, Network Virtualization, Data Visualization, Data Manipulation, 4G LTE, and more.
References
[3GPP_Plan] http://www.3gpp.org/images/articleimages/ongoing_releases_900px.JPG
[IAB] 3GPP, TR 38.874
[3GPP_eV2X] 3GPP, TR 22.886
[3GPP_NR-U] 3GPP, TR 38.889
[NOMA] Yan Chen, Alireza Bayesteh, Yiqun Wu, Bin Ren, Shaoli Kang, Shaohui Sun, Qi Xiong, Chen Qian, Bin Yu, Zhiguo Ding, Sen Wang, Shuangfeng Han, Xiaolin Hou, Hao Lin, Raphael Visoz, and Razieh Razavi, “Toward the Standardization of Non-Orthogonal Multiple Access for Next Generation Wireless Networks,” IEEE Communications Magazine, March 2018.
[3GPP_NonTerrestrial] 3GPP, TR 38.811