5G basicsfazek/English_course_Mobile_communication... · 2016. 12. 7. · 5G network concepts 5G...

5G basics

5G network concepts

5G is a big movement and money nowadays

– ~2020

virtualization&cloud technologies is one key feature of 5G

along with numerous advancements in radio technology and

processing

virtualization -> setting up custom purpose network features

and services easily and rapidly

– ease of development of novel network services

Hálózati Rendszerek és Szolgáltatások Tanszék Budapesti Műszaki és Gazdaságtudományi Egyetem 2

5G network concepts

What is 5G – set of new radio interface technologies/extensions to LTE

• maximum bitrates exceeding 10 Gbps

• can be achieved by applying multi-antenna technologies and large bandwidths

– new bands are needed

– an integration platform

• integrating current and future access technologies, including cellular mobile and local (WiFi)

– a service/application development platform

• new network-based services can be easily set up and run over the 5G networks

• functions/capacities can be set up and tailored to any application’s need easily

– what is an application in this sense: not in the sense of an application on a computer, rather a complete system for a given purpose, using the network

• e.g.: an Intelligent Transportation System (ITS): vehicles and infrastructure communicate; intelligent measurement system: large number of sensors deployed over large area and monitor the area; etc.


5G network concepts

Veriticals

– Vertical is a special network service, used by a special organisation or segment, for a special purpose

• e.g. the ITS, or can be eHealth system; eGovernment system; industrial networks, etc.

• PPDR: Public Protection and Disaster Relief

• MMTC Massive Machine Type Communications

– aka IoT (Internet of Things) from a different perspective. IoT perspective: things are on Internet, what to do with them? 5G perspective: how to design a network that is optimal to connect large number of things

• traditionally these have their separate own network

Network slicing

– a slice of the 5G network: set of functions, software and hardware elements that serve a given vertical application

– they use the same 5G system now, but get service in a quality that is equivalent to having a dedicated network


5G network concepts

5G key application areas and properties

– 1. very high throughput and capacity

• several Gbps peak rate and capacity, high definition video

and gaming, events attracting massive amount of people,

etc.

– 2. very large number of devices, with low data rate each (this is

the MMTC)

• sensor systems, factories, vehicular systems

– 3. Ultra-reliable, low latency applications

• tele-medicine, vehicular applications, PPDR


5G required properties

Key properties for said areas – MMTC:

• nodes use battery, should last for 10 years at least-> minimum power consumption

• cheap, not accurate devices, hard to synchronise

• low datarate, low amount of data rarely but a large number of devices

• radio interface and protocols should support these requirements

• in LTE Release 13 already: Narrowband IoT (NB-IoT) channels, procedures are defined

– PPDR

• group calls, Push to Talk (PTT) operation

• high availability and resiliency

• DMO (Direct Mode Operation): mobiles directly send data to each other („walkie-talkie mode”)

• isolated operation: a single base station without connection to the network can serve as a network for the mobile in its surroundings

• support in LTE: MCPTT (Mission Critical PTT) priorities; ProSe (Proximity Services); IOPS (Isolated Operation)


5G required properties

Key properties for said areas

– ultra-reliable, low latency

• 1 ms end to end round trip time is often mentioned

• if it is end to end, then the two endpoints may not be

physically further than 150 km

• services should be brought close to the users physically

How the network will support all these?

– using NFV (Network Function Virtualization)

– cloud technologies

– SDN (Software Defined Networking)


NFV basics

NFV in nutshell

do what is possible in software

– running on standard servers

• maybe with some extra features/hardware components

– instead of custom designed and built hardware devices

• which is the case today

– apply cloud/datacenter technology and virtualization

cloud/datacenter/virtualization

– large number of compute (processor, RAM), storage (HDD,

SSD) –> server and networking hardware (switches, interface

cards) resources in a datacenter

– virtualization: virtual machines can be set up and run easily, that

use parts of phy resources


Virtualization basics

virtualization

– abstraction between the physical resources and their logical

representation

can be implemented in various layers of a computer system

or network

– storage virtualization

– server virtualization

– network virtualization

long history in computer technology

– virtual machines

– virtual servers

– running several computers on a single hardware



traditional

– single OS (Operating System)

image per machine

– software and hardware tightly

coupled

– running multiple applications

on same machine may create

conflict

– underutilized resources

– inflexible and costly

infrastructure



hosted architecture

– installs and runs as an

application

– relies on host OS for

device support and

physical resource

management

e.g. running a Linux

emulation on a Windows

system



Bare-Metal (Hypervisor) Architecture

– lean virtualization-centric kernel: the hypervisor

– it has direct access to the hardware resources, a hypervisor is

more efficient

• gives resource to VMs (Virtual Machines) as if the VM was

running on those resources

– Service Console for agents and helper applications


NFV in nutshell

analogy:

– smartphones

– common hardware and operating system(s)

• (with some special hardware features, sensors)

– applications solve what was dedicated device earlier

– great number of 3rd party application developers


NFV in nutshell

mobile phone analogy

– devices: dedicated hardware

– apps + special hardware pieces


NFV in a nutshell

source: ETSI NFV whitepaper


Network functions Fields of Application and Use Cases

– Carrier Grade-Network Address Translation (CG-NAT), routers

– Mobile network nodes:

• HLR/HSS, MME, SGSN, GGSN/PDN-GW, RNC

• Node B, eNode B (at least partially)

– home router, set top box in home environment

– tunnelling gateway elements: IPSec/SSL VPN gateways

– traffic analysis: Deep Packet Inspection (DPI), perfomance measurement devices, statistic collections

– Service Assurance, SLA monitoring, Test and Diagnostics

– signalling nodes, IMS

– converged and network-wide functions: AAA servers, policy control and charging platforms

– application-level optimisation: Content Delivery Network (CDNs), Cache Servers, Load Balancers, Application Accelerators

– security functions: firewalls, virus scanners, intrusion detection systems, spam protection


NFV benefits

reduced equipment costs and reduced power consumption

through consolidating equipment and exploiting the economies

of scale of the IT industry

– ~9.5M servers shipped in 2011 compared with ~1.5M routers

forecast for 2012

increased velocity of Time to Market by minimising the typical

network operator cycle of innovation

enable network operators to significantly reduce the maturation

cycle

possibility of running production, test and reference facilities on

the same infrastructure

services can be rapidly scaled up/down as required

service provisioning remotely in software without site visits

required to install new hardware/software Hálózati Rendszerek és Szolgáltatások Tanszék

Budapesti Műszaki és Gazdaságtudományi Egyetem 18

NFV benefits

virtual appliance market to pure software entrants, small

players and academia

optimisation of the location & assignment of resources to

network functions automatically and in near real time

reduced energy consumption by exploiting power

management features in standard servers and storage, as

well as workload consolidation and location optimisation


NFV benefits

Improved operational efficiency

– higher uniformity of the physical network platform

– automated installation, scaling-up and scaling out of capacity, and

re-use of Virtual Machine (VM)

– no need for application-specific hardware

– skills base for operating standard high volume IT servers is much

larger and less fragmented than for telecom-specific network

equipment

– Reduction in variety of equipment for planning & provisioning

– repair failures by automated re-configuration and moving network

workloads onto spare capacity using orchestration mechanisms

– reduce the cost of 24/7 operations by mitigating failures

automatically.

– support in-service software upgrade (ISSU) with easy reversion


NFV challenges

Performance Trade-Off.

– standard hardware (no accelerators) -- probable decrease

in performance

– as small as possible by using appropriate hypervisors and

modern software technologies

– latency, throughput and processing overhead

– available performance of the underlying platform has to be

clearly indicated

– virtual appliances should know what they can get from the

hardware

– virtualisation not only of network control functions but also

data/user plane functions


NFV challenges

Migration, co-existence & compatibility

– NFV must co-exist with network operators’ legacy network

– compatible with existing Element Management Systems,

Network Management Systems, OSS and BSS,

– compatibility with existing IT orchestration systems

– architecture must support a migration path to open

standards based virtual network appliance solutions

– hybrid network composed of classical physical and virtual

devices

– use existing North Bound Interfaces (for management &

control) and interwork with physical appliances


Some notes on NFV

„using commodity standard server platforms”

– in fact, there’s a lot of processing where hardware acceleration can help a lot

• coding, error checking, packet fragmentation/reassembly

• cryptographic coding

• radio processing

– big players of IT industry also use custom-designed and optimized server hardware for their purpose

– so for telecom purposes usage of different servers is foreseen

• NFV maybe running on other platform, but with suboptimal performance

• at least the networking hardware is to be non-conventional

– telco vendor joins forces with IT vendor

• instead of vendor 1 SW+HW -> Vendor 1 SW + Vendor 2 HW or Vendor 1 SW + Vendor 2 Hypervisor

• at least not different HW for different functions


Some notes on NFV

„enabling 3rd party application development”, „development

of new services by the operator”, „openness”

– problem: today telco operator is a bitpipe, big money is taken by

over the top service providers (google, facebook, etc.)

– operators want to get extra money for extra services, easily

programmed and deployed on their own

• or let 3rd party develope and offer own services for some

fees

– trust issues

– was similar motivation in IMS/app servers

• not really happened


Forwarding graphs

VNF forwarding graphs

– the series of network functions to be performed on the traffic

(packets)

– e.g.:

• firewall: who is the sender, is it allowed? ->

• Deep Packet Inspection: is the application type of traffic

allowed?

• traffic analyser: collect statistics

• if email, sent to email server

– is it a spammer or not?

• if other, send to end user equipment


Forwarding graphs

instead of physical machines implementing the functions

and that are connected physically

– functions are connected logically

– theoretically independently of physical connectivity

– however, the physical connectivity of devices running the

VNFs should make sense

– in practice: in a common data center

today: usually mixed solution, different physical machines

run several functions each


SDN basics

SDN in nutshell

Software Defined Networking

separates control functions and packet forwarding functions

– considers networking (packet forwarding) equipment

• routers (conservative definition: looks at IP address and

forwards based on it)

• switches (Ethernet switch: looks at Ethernet address and

forwards based on it)

• in more general terms: switch: looks at headers of various

protocols contained in the information packets and behaves

accoringly

control: how to behave, based on the content of the headers

SDN: to do this control remotely, automatically, in a software

defined manner


Why SDN

complexity: – abundance of networking protocols and features for specific use cases

– old technologies recycled as quick fixes to address new business requirements

– vendor specific features, implemented through proprietary commands

inconsistent policies – security and quality‐of‐service (QoS) policies in current networks need to be

manually configured or scripted

– policy changes extremely complicated for organizations

– manual configuration is prone to error -> many hours of troubleshooting

– if applications/services were removed -> to remove all the associated policies from all the devices

scalability – workloads change and demand for network bandwidth increases

– oversubscribed static network or grow with the demands

– traditional networks are statically provisioned in such a way that increasing the number of endpoints, services, or bandwidth requires substantial planning and redesign


Why SDN

command line example


Why SDN

switching, routing: based on header fields


IP packet

Ethernet frame

TCP packet

Why SDN

principles


SDN principles

separate control plane and data plane entities

execute or run control plane software on general purpose

hardware

decouple from specific networking hardware

– use commodity servers

have programmable data planes

maintain, control and program data plane state from a

central entity

an architecture to control not just a networking device but

an entire network.


SDN architecture

source www.opennetworking.org


SDN architecture

SDN controller

– the centralized repository of policy and control instructions

for the network or application infrastructure

– provisions network services consistently and provides

network information and analytics across all network

resources: LAN and WAN, wired and wireless, and

physical and virtual infrastructures

control software:

– to implement policies

– using APIs on the controller


SDN architecture

e.g. companies A and B, as customers of the network operator requesting 100 Mbps connectivity between their premises with latency not more than 10 ms but A request 500 Mbps in peak hours

state: provided bitrate and latency to each customer, adjust: forwarding capacities, according to measured state

the throughput for A falls below 500 Mbps in peak hour (1), SDN controller instructs the network for adding more forwarding capacity; physically this may use different path (2)


Date post:	10-Mar-2021
Category:	Documents
Upload:	others
View:	2 times
Download:	0 times

5G basicsfazek/English_course_Mobile_communication... · 2016. 12. 7. · 5G network concepts 5G...

Documents