5G SA(StandAlone)의 Key Issue

앞서 언급한 것 처럼 

5G는 다양하게 소개되어 있다.

 

kolobi.tistory.com/entry/4G%EC%99%80-5G-%EB%B9%84%EA%B5%90?category=459865

4G와 5G 비교

 

5G SA가 상용화 된다면 어떤 서비스가 가능할까?

 

3GPP 표준에서 제정한 5G의 서비스는 아래와 같다.

 

URLLC , Network Slicing, IIoT/V2X, 5GC 

 

이제 하나씩 살펴보자.

 

1. URLLC

URLLC는 초저지연이다.

초저지연이라고 하면 네트워크 사업자의 관점에서 본 것이고 사용자의 입장에서는 접속속도가 줄어든다는 의미이다.

LTE만해도 네이버 접속페이지가 빠른데? 뭐가 더 좋아? 라는 질문을 할 수 있다.

우리가 흔히 말할때 이건 B2B로 접근해야된다.

예를 들면 테슬라의 자율주행을 생각해보자.

 

테슬라가 자율주행을 위해서는 무선네트워크가 핵심이다.

앞차와의 거리, 교통상황들 실시간으로 지연없이 전송된다면 이는 안전이 보장되는 것이다.

V2X 뿐만 아니라 다양한 산업분야에서 적용이 가능하다.

즉, 유선을 대체할 수 있는 무선 기술인 것이다.

 

URLLC allows a network to be optimized for processing large amounts of data with extremely low latency and high reliability. This requires sub-millimeter latency with 10-5 block error rates. URLLC uses mini-slot scheduling, the smallest scheduling unit which supports short transmission duration with the reduced processing time, and UL grant free transmission to achieve low latency requirements. By using the UL grant free transmission, a UE does not need to wait for the gNB to assign resources. Network slicing and Multi-access Edge Computing (MEC) can leverage URLLC service effectively. Network slicing enables isolated slices for URLLC and can assign dedicated resources only for URLLC. Equally as important, MEC can dramatically eliminate network delays by hosting services at the edge in close proximity to the customers. URLLC is particularly effective for latency sensitive services or mission critical IoTs, and allows several new business use cases such as remote surgery, autonomous driving, real time traffic information service and remote robot management in factory environments. Figure 6 shows the areas in which URLLC can be applied and the requirements for each area.

 

 

 

2. Network Slicing

 

Network Slicing은 네트워크 사업자 또는 대형 기업에 좋은 솔루션이다.

사용자는 크게 체험하지 못하는데 예를 들면 현대중공업의 사내망을 생각해보자.

우리가 흔히 생각하는 사내망은 유선이라고 생각되는데 무선망을 사내망으로 사용 할 수 있다.

사내망을 기지국만 구축하는 것이 아니고 LTE에서는 별도의 코어망(EPC)을 구성하여 보안을 보장한다.

Network slicing은 별도망을 구축하지 않고 가상화 솔루션을 활용하여 마치 별도의 망이 있는 듯이 만들어 주는 기술이다.

 

Network slicing is the concept of creating logically divided multiple end-to-end virtual networks on a common physical infrastructure without constructing a separate network. In 4G, network slicing was provided in the limited form of isolating a service within a common infrastructure such as Multi Operator Core Network (MOCN) or Dedicated Core Network (DECOR). In 5G, however, network slicing will allow operators to create virtual data pipelines as well as control/management functions for each type of service, thereby assuring the QoS for each service. Figure 7 shows how virtual networks are separated and managed for each service type such as eMBB, mMTC and URLLC within a common infrastructure. Network slicing is able to guarantee the quality of data transmission for time-sensitive services or mission-critical services such as connected cars by allocating isolated and dedicated resources. Ultimately, an operator will be able to leverage this technology to enable new revenue streams [5].

 

3. IIoT/V2X

 

IIoT는 V2X와 연관되어 있다. 사물인터넷이라고 하는데 IoT는 흔히들 알 것이다. 산업에서 사용되는 것이 IIoT이다.

앞서 언급한 자동차 관련된 기술은 V2X이다.

 

Machine-Type Communication (MTC) services such as enhanced MTC (eMTC) and narrow-band Internet of Things (NB-IoT) have already been introduced and served in legacy LTE network. In 5G, the MTC technology has been enhanced to mMTC, which is capable of serving extremely high connection densities (up to 1 million devices per km2) that is 10 times greater than the maximum number served by a LTE network. In addition, ultra- reliable mMTC is able to provide ultra-reliable low-latency communication for network services with extremely challenging requirements on availability, latency and reliability, such as Industrial Internet of Things (IIoT) and Vehicle-to-everything (V2X). IIoT is utilized for controlling applications of automated systems in various areas such as smart factory, gas/water metering, city light management, transport traffic management, and asset tracking/monitoring. These applications require the network that they run on to be ultra-reliable, highly available, and very low end-to-end latency. V2X enables various solutions for Vehicle to Vehicle (V2V), Vehicle to Infrastructure (V2I), and Vehicle to Pedestrian (V2P) communication. V2X has several use cases such as vehicle platooning (coordinated driving with collision avoidance), semi/fully-autonomous driving, remote driving, and real-time information exchange through sensors. Also, V2X enables in-car entertainment services such as movies, TV streaming, and voice conference call. V2X services demand high data rates, very low latency, and high reliability simultaneously, and these requirements can be met by using native 5G services such as eMBB and URLLC. For example, vehicle platooning and autonomous/remote driving require very low latency and high reliability, for which URLLC service is suitable, while the use of cameras and accident monitoring requires high data rate which can be supported by eMBB. If further guarantees on latency and reliability are required, eMBB/URLLC services can be combined with other 5G services such as MEC and network slicing.

 

4. 5GC

5GC는 5G Core이다.

아래는 삼성전자의 부연 설명이다.

 

5GC holds a key role in realizing the full potential of 5G services. Without 5GC, fully-fledged NR services cannot be obtained. 5G NSA deployment leaning on legacy LTE network and EPC allows for a quick launch of 5G services, but also hinders the realization of 5G’s full potential. In 5GC, a cloud native design is introduced to enable flexible scaling and upgrades. The fundamental concept of a cloud native 5GC is defined as 'stateless micro- services deployed in a container-based architecture’. A Network Function (NF) is comprised of small service units called NF services (i.e., micro-services), and NFs store their state information in a central database called Unstructured Data Storage Function (UDSF), which turns the network function itself, stateless. Stateless NFs can be scaled easily and specific NFs can be isolated in case of failures, which in turn makes an uninterrupted service possible. Each micro-service runs in a container and is independently scalable and re-usable. These design characteristics enable the flexible launch of new services, faster time-to-market, and offers enhanced scalability. As a result, the 5GC functions can be quickly created, deployed, and scaled, using automated lifecycle management.

With the introduction of 5GC and NR SA, enhanced features such as RRC inactive state, end-to-end network slicing can be applied. RRC inactive state allows a network to suspend and resume to/from inactive state, so as to allow a UE to return to a connected state as soon as possible from an inactive state. Accordingly, this leads to significant reduction in RRC signaling, and therefore latency and battery consumption are reduced as well.

Samsung 5GC is designed for cloud native based on micro-services, containers and stateless architecture. In addition, Samsung provides a common core solution that combines network functions from EPC and 5GC which support LTE, NR (NSA and SA), and non-3GPP accesses, including Wi-Fi and fixed broadband. A unified authentication process supports multi-RAT access technologies [6]. The Samsung 5G Common Core solution reduces the cost of maintaining EPC and enables the expedient introduction of 5G services in full scale without impacts on legacy services.