What is 5 G ?
I don't know -:). Nothing about 5G is defined officially in any standard organization as of now. However there are several organization that describes key technical component or key performance indicator (KPI) that may envision on what 5G will be like. I would put the list of features from several different organization.
Initial Definition
When the first talk about 5G started and some of prototyping test result came out, the focus was mainly around throughput. (This kind of focus hasn't been changed much until mid 2013)
At least, one thing for sure will be that the data rate will be at least several G bps. (The final goal of 4G data rate is 1 Ghz and we still have a long way to go to achieve this 1Gb rate).
By now (as of Nov 2015), you may see a couple of dozen whitepapers about the 5G. If you read through all of these whitepapers, you would notice that the key concepts they claim in the documents are almost same. Personally, I would recommend you to read through the documents from METIS. I think METIS documents are by far the most extensive and most in-depth. The only problem is that those
documents are too thick :)
Followings are some of my personsl keywords about the 5G reading through most of these papers.
Keywords
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Description
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Extremly High Data Rate |
By far, we don't know yet (as of Nov 2015) what would be the maximum throughput. But I think it will be targeted to be at least around 10 Gbps. |
Extremly Low Data Rate |
Just achieving the extermly low throughput has no technical problem. But critical technological issue is that achieving the extremely low data rate with extremly low cost and extremely low energy (battery) consumption. Refer to MTC criteria for the details. |
Extremly Low Latency |
We don't know yet (as of Nov 2015) what would be the target latency. But by far, around 1 ms latency are the most commonly mentioned number. (In terms of subframe length, it would be around 100us or 200 us)
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Super High Frequency |
The words 'High Frequency' or 'Low Frequency' can be misleading because it would be a relative concept, but I say 'Super High Frequency' comparing to current cellular communication frequency (mostly under 3 Ghz). By far (as of Nov 2015), the most frequently commented frequenty blocks are 6 Ghz, 15 Ghz, 20~30Ghz and the highest frequency being tried is a little bit over 70 Ghz.
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Super Wide Bandwidth |
The words 'Wide Bandwidth' or 'Narrow Bandwidth' can be misleading because it would be a relative concept, but I say 'Super Wide Bandwidth' comparing to current cellular communication bandwidth (100 MHz, ideal max in 4G). The most commonly mentioned bandwidths are 160 Mhz, 400 Mhz, 800 Mhz. Currently the widest bandwidth being mentioned are 2 Ghz bandwidth.
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Softwares as much as possible |
Many components in core network would be software based and with this it would become very flexible and accomdate news features in short time frame |
Build up Intuition on 5G
Before you read, just enjoy these video clips and let your brain build up its own intuition(Insight).
Definition by METIS
More organized and formal definition can be made from METIS which were proposed in Aug, 2013. Even though METIS does not put forth explicit 'definition', it proposes several KPI (Key Performance Indicator). I think we can say "A communication system satisfying the METIS KPI can be categorized as 5G".
Following is the list of KIPs and test cases performing the measurement of KPIs proposed by METIS. (Refer to D1.1 and D2.1 METIS document for details)

Technical Requirement proposed by METIS to meet 5G goal are :
- 10-100 times higher typical user data rate, where in a dense urban environment the typical user data rate will range from 1Gbit/s to 10Gbit/s;
- 1,000 times more mobile data per area (per user), where the volume per area (per user) will be over 100 Gbps/km2;
- Support for 10-100 times more connected devices;
- 10 times longer battery life for low-power massive machine communications where machines such as sensors or pagers will have a battery life of a decade;
- Support of ultra-fast application response times, where the end-to-end latency will be less than 5ms with high reliability;
- Ability to fulfil these requirements under a similar cost and energy dissipation per area as in today’s cellular systems.
Definition by 5GNOW
5GNOW does not decribe much about high level definition or use model of 5G. I guess any 5G high level definition fall into the scope of METIS definition/use model. 5GNOW discuss more on lower level impelmentation of 5G. Key implementation Item discussed/proposed by 5GNOW is as follows.

After I've read most of 5GNOW Deliverable document, the key words that pop-up consitantly in my mind are
- Asynchronous
- Bursty low data rate transmission
- Enhanced PRACH
Think on your own why these would be issues and then refer to 5GNOW Deliverable Documents.
Definition by SKT
Following came from the white paper issued by SKT (SK Telecom, South Korea)

Following table also comes from SKT WhitePaper . To be honest, I am not sure how much of these items will be eventually adopted by the industry standard, but I think this can be a good list of starting points if you want to do some more detailed research on specific technologies for future
communication. I recommend you to read the original WhitePaper a couple of times and search the related document (e.g, Related Paper and Thesis for each items)
1. Realistic UX and 5G Contents Process |
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Object/space Recognition |
Fast Recognition of surrounding objects and spaces by a camera or sensors |
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Real Time Rendering and Display |
Display(Rendering) of an object in realtime recognized by glass or HMD |
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Real Time Hologram Processing |
Reconstructing a real image of an object with 360 degree field of view in 3D space |
2. Efficient Processing & Transmission of Tactile Multimedia |
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MMT(MPEG Media Transport) |
a special MPEG technology to minimize latency in media transmission in All-IP network |
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High Efficiency Multimedia Coding |
Multimedia Coding Technique for efficient creation/transmission of realistic 3D multimeidia contents (e.g, MVC : Multi-view Video Encoding) |
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Cloud-based Computing, Caching and Orchastration |
Dynamic Allocation and Orchestration of cloud resource and caching to process realistic high volume multimedia |
3. Cloud-based All-IP Network and Service Platform |
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NFV-based Virtualied Core Network Operation |
Techniques to build the cloud by virtualizing a standard hardware and operate a range of networ/service functions on the software-based network. |
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Virtualized RAN |
Techniques to centralize and virtualize DU(Digital Unit) of a base station into a standard HW based cloud and process RAN signals in real time. |
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SDN and integrated Orchestraion |
Effective control and lifecycle management of the software-based network services from a centralized & unified network service orchestrator |
4. Analytics-based Network Intelligence & Optimization |
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Big Data Analysis |
Techniques to process, analyze and infer large volume of multi-dimensional/unstructured data |
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Network Intelligence & Analysis |
Techniques to optimize operation and performance of networks from information on performance, log, traffic |
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Analytics-based SON |
Techniques to automatically detect abnormality, to optimize and take necessary measures |
5. Fast, Flexible Transport Network |
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POTN (Packet Optical Transport Network) |
All-IP/All-Optical transport technology that converges multiple layers to increase simplicity and efficiency of network |
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Transport SDN |
Integrated Networking technology to efficiently use and automatically control network resources in multi-layer, multi-vendor, multi-domain networking environment |
6. Beyond-Cellular Network Architecture |
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Direct D2D Communication |
Techniques to directly share information and data between devices |
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Contents Centric Networking (CCN) |
A network architecture that stores content in a transport equipment on the network path and provides it by a mapped name of content |
7. Enhanced Operation for Multi-cell/HetNet |
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Elastic Cell |
Techniques to dynamically select and communicate with a cell best for the user's current channel environment in real time |
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Aggregation of Heterogeneous Networks |
Techniques to improve data rate by combining cellular networ with different networks such as WiFi or with unlicensed LTE band |
8. Ultra-Dense Small Cell |
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Dynamic interference control and coordination |
Techniques to improve signal Quality at cell edges by enabling nearby cells to cooperate in real time |
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HetNet SON |
Techniques to automatically optimize wireless network operation in diverse cell environment to improve QoS |
9. Wideband High Frequency RF & 3D BeamForming |
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3D BeamForming |
Techniques that provies RF environment for high-speed transmission by controlling electromagnetic waves or forming multiple beams in the vertical and horizontal directions |
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Beam Switching/Tracking |
Techniques that provides an optimal link by selecting an optimal beam out of many or changing the direction of the antenna beam according to the location of the user. |
10. Enhancement of Multiple Antenna Technology including Massive MIMO |
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UE-Specific Beamforming |
Techniques that suppresses mutual interference between multiple terminals by utilizing independent and sharp beams |
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CSI/CQI Feedback |
Techniques that enhances accuracy of CSI and CQI while minimizing uplink signaling overhead |
11. Advanced IoT & New Waveform/Duplex |
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Cellular-based MTC (Machine Type Comm) |
High Capacity multiple access & machine data processing technology to support IoT service on mobile communication network |
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New Waveform (NOMA, FBMC) |
Transmit and receive technology that increases efficiency of accommodating multiple users and data through reciever interference cancellation and filter-based interference supporession |
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Hybrid duplex & Full Duplex Communication |
Flexible allocation scheme for DL/UL resources and simultaneous transmit and receive technology based on self - interference cancellation |
Definition by 4G America
The contents in this section is based on the WhitePaper : 4G Americas' Recommendations on 5G Requirements and Solutions.

Definition By NTT DoCoMo
The contents in this section is based on the WhitePaper : 5G Radio Access: Requirements, Concept and Technologies - DOCOMO 5G White Paper
< Trends in Technology and Motivation for 5G >
This trend is mainly represented as M2M, MTC, IoT these days. Actually each component technology is already available and has been adopted by various area, but they hasn't been integrated across wide area. We need a flexible cellular network that can integrate all of these diverse component and 5G will be playing a crucial role for this.
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These are emerging technolgies meaning relatively new technology, but development/implementation for each components has been adopted for a while. But this hasn't been a target for cellular communication since the required data rate is too high. To connect these applications to cellular network, we need a new celluar technology that support extermely high data rate. This extremly high data rate will be one of the key
feature of 5G.
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< Key Requirement >

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