Early lessons from Open RAN Deployment in brownfield ,a must delivery model to untap 5G Scale,Complexity and economy in 2021+

With most of Tier1 Operators rolling the ball for early experience of 5G Standalone based on 3GPP Release-16 that can offer very new and unique experiences to 5G  around uRLLC and mIOT along with improved QOS for broadband the whole industry is looking forward to accelerate 5G adoption in 2021 .

This is an ideal time for the industry to find new ways to improve human life and economy in the post covid world . However the biggest problem with 5G experience so far has been the Delivery model that can offer both Cost and Scale advantages . With the hyperscalers eyeing the Telco billion dollar market it is necessary for all vendors and Telco’s themselves to analyze and find ways towards new business models that are based on

• Coherence
• Data Driven
• Service Quality

By coherence I mean when we go to 5G Radio site what components will be residing there

• A 5G Radio site components
• Edge Applications
• Network connectivity

By Data I mean till now depsite dleiverying thouand’s of 5G sites we can not offer DaaS(Data as a service) to vertical’s the only visibiltiy we have is on horizontal interfaces in a 3GPP way .

The third and the most important piece is RF and RAN service . You talk to any RAN guy and he is not interested in both Coherence and Data unless we answer him a RAN service that is atleast same lr better the legacy .

This makes the story of Open RAN very exciting to analyze and this is the  story of my experience of leading such projects during last years in both Company and Industry . This is my humble opinion that Open RAN and other such innovative solutions must not be analyzed only through tehnology but an end to end view where some use cases are specificcally requiring such solutions to be succcessful .

Why Open RAN

For me the Open RAN is not about Cloud but finding a new and disruptive Delivery model to offer RaaS (RAN as a service). Have you ever imagined what will happen if a Hyperscaler like AWS or Azure acquire a couple of RAN companies who can build a Cloud Native RAN Applications  , the Telco can order it online and it can be spined in the Data center or on the Edge Device in a PnP(Plug and Play manner)

If you think I am exaggerating  already there are disucssions and PoC’s happening aorund this . So Open RAN is not about Cloud but about doing somethnig similar by the Telco Industry  in a Open and Carrier grade fashion .

This is where Open RAN is gaining momentum to bring power of Open , Data driven and Cloud based disaggregated solution to the RAN site .Future of Telco is a well-designed software stack that extends all the way from Core the last mile Site of Network  Crucially, it also allows for placing more compute, network and storage closer to the source of unrelenting volume of data – devices, applications, and end-users.

There is another aspect which is often overlooked which is transport cost , as per filed trial result use of Open RAN CPRI interface 7-2 increased the front haulf capacity utilziation by at least 30-40% primarily as there are lot of propietry overheads in CPRI world .

“For CXO it means  at least 30-40% direct savings on Metro and transport Costs”

What is Open RAN

5G RAN has a huge capacity requirements and naturally to scale this network disaggregation and layered network architecture is the key . Open RAN architecture can be depicted as follows .

RU:

Radio Unit that handles the digital front end (DFE) and the parts of the PHY layer, as well as the digital beamforming functionality .It is almost same architecture as in DBS (Distributed Basestation) architecture fofered by many legacy vendors . Conceptually AAU (Active antenna unit) is considered together with radio unit

DU:

Distributed unit handles the real time L1 and L2 scheduling functions mainly MAC split . it is realt time part of BBU (Baseband unit)

CU:

responsible for non-real time, higher L2 and L3 , it is non real time functions of BBU like reosurce pooling , optimization etc

RIC:

RAN Intelligent contorller is the intelligence component of Open RAN that will collect all data and offer insights and innovation through xAPPS . similarly it cooperates with NT-RIC (Non real time RIC) which is part of ONAP/MANO to offer end to end end SMO (Service management and Orchestration) functions  

Interfaces of Open RAN

When it comes to understand Open RAN we need to understand both those defined by O-RAN and those by 3GPP and this is so important as it do require cross SDO liaisonship

O-RAN interfaces

• A1 interface is the inerface between non real time RIC /Orchestrator and RAN components
• E2 interface is the interface between NT-RIC (RAN Intelligent Controller) and CU/DU
• Open FrontHaul is the interface between RU and DU mostly we are focusing on eCPRI 7-2 to standardize it
• O2 interface is the interfaces betwee NFVI/CISM and Orchestrator

3GPP interfaces

• E1 interface  is the the interface between CU-CP (control plane) and CU-UP (user plane)
• F1 interface is the interface between CU and DU
• NG-c is the interface between gNB CU-UP and AMF in 5G Core Network

To solve all interface and use case issues the ORAN Alliance is working in a number of streams  to solve issues .

• WG1: Use Cases and Overall Architecture
• WG2: The Non-real-time RAN Intelligent Controller and A1 Interface
• WG3: The Near-real-time RIC and E2 Interface
• WG4: The Open Fronthaul Interfaces, 
• WG5: The Open F1/W1/E1/X2/Xn Interface
• WG6: The Cloudification and Orchestration
• WG7: The White-box Hardware Workgroup
• WG8: Stack Reference Design
• WG9: Open X-haul Transport.
• Standard Development Focus Group (SDFG): Strategizes standardization effort. Coordinates and liaises with other standard organizations.
• Test & Integration Focus Group (TIGF): Defines test and integration specifications across workgroups.
• Open Source Focus Group (OSFG): Successfully established O-RAN SC to bring developer in the Open RAN ecosystem

Early Playground of Open RAN

The change in world economy impacted by geo political factors like a drive to replace Chinese vendors from networks like in Australia for national security reasons naturally change momentum to find both less costly and high-performance systems. Naturally one of the prime networks where Open RAN will get introduced are above .It is true that still there are some gaps in Open RAN performance mainly on the Base band processing and front haul but there are some use cases in which Open RAN already proved to be successful as shown below , the key point here is that although there are some issues but with some use cases ready it is important to introduce Open RAN now and to evolve it in a pragmatic way to ensure they can coexist with traditional RAN solutions

• Private 5G Networks
• Rural Deployment e.g 8T8R FDD
• In building solutions
• Macro sites

TIP Open RAN Project Progress

TIP A.K.A Telecom Infra Project is an Open-source project looking after a number of disruptive solutions that can make 5G networks both cost efficient and innovative. Below are some highlights on our progress in the community till 2021

A1: Built the Reference architecture for Multi vendor validations

Through support of operators, vendors and partners built a complete reference architecture to test and validate the complete stack end to end and SI integration

A2: Built the Reference architecture for Multi vendor validations

Worked to define the define the complete RFX requirements for Open RAN and it can be retrieved as below

TIP OpenRAN_OpenRAN Technical Requirements_FINAL

tip-openran_openran-technical-requirements_finalDownload

A3: Use cases of Open RAN success

In 2020 and better part of 2021 the community have worked tirelessly to couple Open RAN with some exciting use cases to capitalize the low hanging fruits of Open RAN as follows

1. “Context Based Dynamic Handover Management for V2X”
2. “QoE Optimization”
3. “Flight Path Based Dynamic UAV Resource Allocation”
4. “Traffic Steering”
5. “Massive MIMO Optimization”
6. “Radio Resource Allocation for UAV Applications”
7. “QoS Based Resource Optimization”

O-RAN+Use+Cases+and+Deployment+Scenarios+Whitepaper+February+2020

o-ranusecasesanddeploymentscenarioswhitepaperfebruary2020Download

A4: Success through RIC (RAN Intelligence controller)

There are two-fold advantages of RIC introduction in Open RAN architectures mainly first for RAN automation for both Managmeent and KPI optimization and secondly bring new and disruptive use cases through xAPPS and data driven operations including

1. Smart troubleshooting of RAN
2. RAN parameter optimization using AI
3. Capacity predicting
4. New Use cases by exposing API’s to 3^rd part developer

A5: RAN configuration standardizations

Benchmarked a number of RAN configurations to be deployed in the field including

1. Small cells mainly for SME and in building
2. Low-capacity Macro (Rural)
3. High-capacity Macro (Highways)
4. RAN parameter optimization using AI

Highly encourage to join TIP to learn more

https://member.telecominfraproject.com/

A6: Chip advancements brought prime time for Open RAN with 64T64R trial in 2021

Customers realy on 5G massive multiple-input and multiple-output (MIMO) to increase capacity and throughput. With Intel’s newest Intel Xeon processors, Intel Ethernet 800 series adapters and Intel vRAN dedicated accelerators, customers can double massive MIMO throughput in a similar power envelope for a best-in-class 3x100MHz 64T64R vRAN configuration”

Challenges and Solutions

In last two years we have come far to innovate and experiment with a lot of solutions on Open RAN , the list of issues we solved are huge so lets focus on only the top challenges today and how we are solving them today, let’s say to set a 2021 target our target is by the time O-RAN alliance  freezes coming releases Dawn  (June 2021)  and E Release (Dec 2021) we as a  community are able to fix those top issues as below .I apologize to leave down some less complex issues like deploy Open RAN , focus groups key interfaces specifications status specially momentum around 7-2 etc . I feel I ran of time, pages and energy and I fear I will test your patience with a bigger tome

P#1: Ecosystem issues in Open RAN

Based on our field trial we found for 8T8R we can achieve around 40% of cost reductio with Open RAN with the future transport architectures like “Open ROADM” we can build whole RAN network in open manner and achieve great cost and efficiency advantages. However when components are from different vendors the non-technical factors to make it successful is really challenging e.g

• How to convince all team including RAN guys that what we are doing is right J and we should get rid of the black boxes
• How to let all partners work together in a team which are historically competitors
• Making software integration teams

P#2: Radio Issues in Open RAN

The Site swap scenarios in most brown field environments require efficient Antennas and Radios that are

• 2G + 3G +4G +5G supported
• Massive Mimo and beam forming support
• Low cost

This is a fact that till now most of effort has been on the DU/CU part but now we need more attention solving the radios and antennas issues .

Lesson we learnt in 2020-2021 is that everything can not be solved by the software as finally every software need to run over a hardware . An increased focus on Radio , Antennas and COTS hardware is a must to acceerate any software innovation

P#3: Improve RAN KPI

No disruptive solution of Open RAN acceptable unless it can deliver a comparable performance to legacy systems like coverage, speed , KPI .

To make Open RAN main stream DT, tools, RAN benchmarking all need to be addressed and not only the Cloud and automation part 

P#4:SI and certification process

We already witnessed a number of SI forms and capabilities during NFV PSI however for a disruptive solution like Open RAN it need a different approach and SI should possess following

• Complete vertical stack validation

Its not just the Cloud or the hardware but the end to end working solution that is required

• Stack should include Radios and Hardware

Certification should consider RF/radio and hardware validation

• Software capability and automation

To make it successful it is very important that SI is rich on bothy tools and capabilities on automation ,data and AI

Source: mavenir

P#5:Impacts of Telco PaaS and ONAP

To make Open RAN real success it is very important to consider this while building capabilities and specifications of other reference Architectures most of which are Telco PaaS and ONAP . If i go to explain this part i fear the paper length will become too long and may skew towards something not necessarily a RAN issue .

However just to summarize the ONAP community has been working closely with Open RAN to bring the reference architecture in upcoming release

and see some of agreed WI’s in below

https://wiki.onap.org/display/DW/5G+Use+Case+Meeting+notes+for+May+to+Dec+2020

Finally for Telco PaaS we are also working to include Telemetry , Packaging and Test requirements for Open RAN stack . Those who interested in these details kindly do check my early paper below

https://nfvsdn5g.cloud/2021/03/23/evaluating-gaps-and-solutions-to-build-open-5g-platforms-and-capabilities/

Open RAN a necessity for 5G era

Early experience with 5G proved that it is about scale and agility, with cost factors driving operators towards an efficient delivery model that is agile, innovative and that can unleash the true potential of network through Data and AI.

In additon as time will pass and more and more use cases will require integration of RAN with 3^rd party xAPPs it will be definite need to eolvve to a architecture like Open RAN that will not only support coexistence and integration with legacy systems but also support fast innovation and fleibiltiy over time  . With early successful deployments of Open RAN already happened in APAC and US its improtant for all industry Catch the Momentum

Those who are proponents of closed RAN systems often say that an Open system can never compare with monolithic and ASIC based systems performance, similarly they claim the SI and integration challenge to stitch those systems far outweigh any other advantage.

The recent advantages in Silicon like Intel FLEX architecture with ready libraries like OPENESS and Open Vino has really made it possible to achieve almost same performance like monolithic RAN systems.

Above all latest launch of #intel 3^rd generation XEON processors are proving to be a game changer in bringing COTS to the last mile sites .

 Above all involvement of SI in the ecosystem means the industry is approaching phase where all integration can be done through open API and in no time making true vision of level4 autonomous network possible. 

Term	Description
DU	Distributed Unit
CU	Control Unit
CP & UP	Control Plane and User Plane
A & AI	Active and Available Inventory
CLAMO	Control Loop Automation Management Function
NFVI	Network Function Virtualized Infrastructure
SDN	Software Defined Networks
VLAN	Virtual LAN
L2TP	Layer2 Tunneling Protocol
SBI	Service Based Interface
NRF	Network Repository Function
NEF	Network Exposure Function
NAT	Network Address translation
LB	Load Balance
HA	High Availability
PaaS	Platform as a Service
ENI	Enhanced Network Intelligence
ZSM	Zero touch Service Management
EFK	Elastic search, Fluent and Kibana
API	Application Programming Interface

Advertisement

Network Slicing and Automation for 5G (Rel-15+) – A RAN Episode

Courtesy of IEEE

Network Slicing is a great concept which has always been an attractive jargon for vendors who wish to bundle it with products to sell their products and solutions . However with the arrival of 3GPP Release16 and subsequent products arriving in market things are starting to change ,with so many solutions and requirements finding a novel slicing architecture that fits all is both technically complex and business wise not making lot of ROI sense . Today we will try to analyze and answer the latest progress and directions to solve this dilemma

Slicing top challenges

Based on our recent work in GSMA and 3GPP we believe below are the top questions both to evolve and proliferate slicing solutions

• Can a Public Slicing solution fulfill vertical industry requirements
• How to satisfy vertical industry that Slicing solution can fulfil their needs like data sovereignty , SLA , Security , Performance
• Automation and Intelligence , can a public slicing solution flexible enough to provide all intelligence for each industry
• Slicing for cases of 5G Infra sharing

Solution baseline principles

When we view Slicing or any tenant provisioning solution it is very important as E2E all layers including business fulfillment , network abstraction and Infrastructure including wireless adhere to the same set of principles .

A nice description of it can be found in 3GPP TS28.553 about management and orchestration for Network slicing and 3GPP TS28.554 KPI for 5G solutions and slicing . In summary once we take the systems view for Network Slicing the principles can be summarized to following

• Slice Demarcation: A way to isolate each tenant and a possibility to offer different features of slicing bundle to different tenants , for example a Large enterprise with 10 features and 20 SLA while for small businesses 5 features and 5 SLA will do
• Performance: A way to build a highly performant system , the postulate is once we engineer and orchestrate it will it work E2E
• Observability : With 4B+ devices added every year and with industry setting a futuristic target of a Million Private networks by 2025 its just a pressing issue how to observe and handle such networks in real time

I think when we talk about Slicing mostly we speak about key Technology enablers like NFV , Cloud , MEC , SDN which is obviously great since a software of Network and Infra is vital . However not speaking about RAN #wireless and WNV (Wireless Network virtualization) is not a just . In this paper i just want to shed some light from RAN perspective , consider the fact still today around 65% of customers CAPEX/OPEX pumping in RAN and Transport it is vital to see this view for both conformant and realistic solution . if NFV/SDN/Cloud demands sharing among few 100’s tenants the RAN demands sharing among Million so resource sharing , utilization and optimization is vital

RAN Architecture

From E2E perspective the RAN part of slice is selected based on GST and NSSAI which is done by UE or the Core Network however its easier said than done when we need to view E2E Slicing following should be considered to build a scalable slicing solution

RAN#1: Spectrum and Power resources

The massive requirements for business towards services and slices require a highly efficient Radio resources , luckily low,mid and high bands combined with Massive Mimo is handling this part however not just spectrum and how to utilize this in efficient manner in form of form factor and power is vital . When we need view RAN view of Slicing its not just the Spectrum it self or RF signal but also the Spectrum management like Macro , Femto and Het Nets including Open cellular . In summary still this part we are not able to understand well as it require some novel algorithms like MINLP (mixed integer non linear) programming which focus to optimize cost while increase resource usage at same time . As per latest trend a tiered RAN architecture combined by new algo like game matching through ML/AI is the answer to standardize this

RAN#2: RAN Dis-aggregation

Just like how NFV/SDN and Orchestration did for Core similarly Open-RAN and RIC (RAN intelligence controller ) will do for RAN . If you want to know more may be you need check author’s writeup about RAN evolution

RAN#3 RAN resource optimize

Based on our Field trials we find the use of Edge and MEC with RAN and specially for CDN will save around 25% of resources , the RAN caching is vital combined with LBO( Local break out) will help Telco’s fulfill the very pressing requirements from verticals . Again this is not just a cloudlet and software issue as different RAN architectures require a different approach like D2D RAN solution , Het Net and macro etc

RAN#4 Mid Haul optimize

Mid haul and Back haul capacity optimization is vital for slicing delivery and today this domain is still in a R&D funnel . A TIP project CANDI Converged Architectures for Network Disaggregation & Integration is some how evolving to understand this requirement

RAN#5 Edge Cost model

Edge solution for Slicing in context of RAN is cost model problem e.g how many MEC servers and location and it can relieve RAN and RF layer processing is the key , our latest work with Telco Edge cloud with different models for different site configuration is the answer

RAN#6 Isolation , elasticity and resource limitation

This is the most important issue for RAN slicing primarily due the the fact that they are different conflicting dimensions viz. extra resource isolation may make impossible to share resources and will limit services during peak and critical times , similarly much elasticity will make isolation and separation practically impossible , solutions for matching algorithms is the answer as it will help to build a RAN system which is not only less complex but also highly conformant . This is a make and break for RAN architecture for slicing

RAN#7 RAN infrastructure sharing for 5G

Today already the Infra sharing has started between ig players in Europe , the one questions that comes what about if a use purchase a slice and service from a tenant ,consider a whole sale view where the Infra is processed by sharing and bundling of resources from all national carriers due to reason that obviously the 5G infra from single operator is not sufficient from both coverage and capacity perspective

RAN#8 RAN Resource RAGF problem

In case of service mobility or congestion how UE can access the resources quickly may be in other sector or sites

RAN#9 Slice SLA

SLA of slices and its real time monitoring is the key requirements of business , however imagine a situation where shortage of shared resource pool make impossible to deliver the SLA

RAN#10 Slice Operations

Slice operations is not just the view of BSS and Operations as real time RAN resource usage and optimization is necessary , Have you ever thought how perfectly managed slice can exist with normal Telco service specially when you find there is a key event and many users will use service . I think this so some dimension still not well addressed . I have no hesitate to say when many CXO’s of enterprise convince them they should opt to build their own 5G private network this is exactly the problem they fear .

Summary

In today’s writeup i have tried to explain both the current progress, challenges and steps to build a successful slicing solution keeping the hat of a RAN architect , i believe this is very important to see the Radio view point which somehow i firmly believe has not gotten its due respect and attention in both standard bodies and by vendors , in my coming blog i shall summarize some key gaps and how we can approach it as still the slicing products and solutions are not carrier grade and it need further tuning to ensure E2E slicing and services fulfillment .

5G Site Solutions Disaggregation using Open RAN

According to Latest Market insights the RAN innovation for Telecom Lags behind others initiative by 7years which means call for more innovative and Disruptive delivery models for the Site solutions specially for next Wave of 5G Solutions .

However to reach the goal of fully distribute and Open RAN there needs to build a pragmatic view of brown fields and finding the Sweet Spot for its introduction and wide adoption .

Here are my latest thoughts on this and how Telecom Operators should adopt it . There is a still a time for industry wide adoption of Open RAN but as yo will find time to act is now .

What you will

What you will learn

• Building Delivery Models for Open RAN in a brownfield
• Understand what,when and how of Open RAN
• What is Open RAN and its relation with 5G
• Current Industry solutions
• Define phases of Open RAN delivery
• Present and Next Steps 5. Architecture and State of Play

Australia continues to innovate 5G with Applications and Industry

How 5G will change the Geo maps and Economy in the Post Covid-19 world , some key initiatives we learn from Australia 5G Ramp

1. Australian Federal Govt to invest more than $21M to boost use of industrial use of 5G across Australia

2. The Key industry Govt want to harness through this grant are agriculture mining, logistics and manufacturing.

3. Attracting top talent in development is key target as 5G comes to life with 1/3 of Aussies already covered by 5G

4. More than $8.1M will improve Spectrum including adoption of DSS and launch of Ku band 26GHz

5. Government plan at least 1GHZ Spectrum availability for uRLCC (Above 279MHZ in US and 300 MHZ in West Europe)

6. Government Smart rollout initiatives plan to increase 5G throughput from 300Mbps to above 1Gbps by 2021+

With Iphone 5G launching this month I am optimistic in all sense AUstralis will keep on as one of leading markets for 5G

#MyAustralia

https://www.canstarblue.com.au/about-canstar-blue/

Top Considerations to build a Future Transport for 5G Networks

source: NEC Future Networks

According to latest reports from leading Trasnport Infrastructure vendors Ericsson and NEC . it is very vital to build Next Era Transport for 5G that can serve for MPLS and SRV6 end to end . When we think of future business cases like End to End Network Slicing it will become for important .

These are

source: Ericsson

Transport for Open/C-RAN

As 5G will deploy in different scnerios and Cloud will be long term most lucrative one so transport must align with it by offering Packet and Ethernet based transport end to end from device to core preferably using e-cpri models that has significant low latency

Outdoor Dense Urban solutions

In Outdoor in city centers laying NG Fiber may not be feasible solution so offering connectivity using PON and MW is needed that is why it is important to not just lock with Fiber solutions

Automation of Transport

Just like others domains like RAN , Core , Edge the transport also need to be Orchestrated and must be optimized over time using ML and AI . the key for this is build a transport that can automate using T-SDN like ACTL workflows or Open ROADM and that can help collect all data that can be optimized with AI .Cool stuff

Future DC architectures

Transport should be flexible not only to offer transport based on 3GPP service model but based on DC architectures like solutions for Clos architecture , DIs-aggregated scnerios etc

Distributed architectures

Just like with other solutions in 5G the transport should be distributed like support for Hub /Be-spoke rather than full mesh for both reliability , performance and scale .

Secure architectures

Security nevertheless is of paramount importance specially as we will open transport for 3rd party and whole sale connectivity although this domain is well addressed in Orchestration and End to End Slicing however as famous adage we must be leave the software boundary un attended .

“Protecting a software with another software in a cloud is not scalable.”

–Saad Sheikh

Disrupting Telco Access rollouts through Open and Dis-aggregated RAN Networks

“Open, Intelligent, virtualized and fully interoperable”

O-RAN alliance

Source: O-RAN

During the last decade the Disaggregation movement which was initially started to address only a handful of business requirements have come far and delivered results. This early success has enabled many verticals to build the robust architectures through which we can solve both current and future business requirements to define a new momentum in a global Post COVID-19 economy.

For CSP and TMT industry specially we have seen Cloud movement is taking full momentum and hence it is becoming more prominent that we can only reap the real advantages from this transformation if the technology building block Lego’s are aligned with new principles to build infrastructure and networks. The list of such principles can be big and daunting however an Architect can start by breaking this list to Top important initiatives viz. 

• New Business models (To expand from Traditional B2C to B2B and Future B2B 2X (SaaS) offerings
• NE coding principles towards Cloud Native
• Focus towards Enterprise offerings
• Automation and efficiency
• Any Access
• Converged Transport and Finally
• Dis-aggregated and Open  RAN

All of these initiatives are inter mingled and has to be achieved along the transformation journey however there are some initiatives which have profound impact on CSP’s   investment and CAPEX/OPEX spending portfolio of which RAN comes to be on the top of list.

RAN(Radio Access Network)  networks which directly connects the subscriber to large Telco Infrastructure encompass to cover more than 5 Billion users  and define 1 Trillion $ Annual global revenue is certainly believed to be the most important infrastructure that we need to modernize and cloudify in an efficient manner .RAN has  historically proved to be a big cash cow for the Telco Industry . Infact  as per our analysis this piece is swallowing at least 70% of Operator CAPEX . So the traditional manner to build RAN networks by building a complete Radio/TXN Network using proprietary is neither attractive to the CFO nor is it scalable to deliver future requirements for new services in the 5G world. In this Paper I will try to share my view point how to start and build Dis-aggregated RAN Networks

How to build the Remote and Edge Clouds

We believe that in future every 5G new site will be an Edge Site which makes it necessary to build both Edge and RAN infrastructure on common and share Cloud Infrastructure. When it comes to define characteristics of this shared infrastructure the most important piece will be the operations and manageability of this large and scalable infrastructure.

Next the most important piece will be the networking primarily because we CSP’s traditionally have been doing this stuff for decades which is to ensure to wire and connect all solutions to offer them as a service to our customer. We have already seen some vendors bringing their commercial offerings to address these points, For example Vmware NSX-T 3.0 and Juniper 2.0 with unified SDN and analytics for all Core, Metro, Edge and Public Clouds. RedHat is another such vendor whose massively scaler AMQB based Openstack and Kubevirt based containerized platform support vision of complete automated infrastructure that is provisioned and managed by a central controller.

Future Disaggregated Hardware

Proponents of Closed RAN (at least from RU to DU) often claims the open X-86 hardware can not compete with high processing and performance required for a real time RAN however with the arrival of O-RAN (Open RAN alliance)  open interfaces , advancements in Silicon and collaborative community driven efforts such as in TIP driven Open RAN has really made it possible to open up the entire network and to build it using common principles using EOM offerings from a diverse suppliers .There are many advances in hardware that need to be carefully tailored to make successful Open RAN like ASICS specially for Network, GPU ,FPGA , NPU according to priorities for time-to-market, cost-performance, and reconfigurability, as well as scalability and SW ecosystem in making decision. Parallel processing-based accelerator can easily handle the performance of OFDMA and massive MIMO. In addition, the use of AI in edge computing is fueling the emergence of new AI processors beyond GPU, with TPU or spatial processor.

One of such recent advancements is Intel P-Series Atom Processor that is best suited to build Open RAN solutions , similarly to converge hardware at the sites Intel has announced the C-series Atom processors primarily which are used to deploy Edge and SD-WAN CPE’s , such a convergence is vital for industry to achieve vision of truly open and converged networks at the Edge and last mile networks .

One key point when we view Hardware modernization for Open RAN is to look advantages of Software e.g DPDK itself, For example the DPDK recent release DPDK19.05 only require 1-2 CPU cores per server so value coming from Smart NICs are declining as industry is reaching a new efficiency on the software. Again the latest offerings from intel chip set is a good example where latest Cascade Refresh is adding 30~40% power at the same cost which will make is possible not only to virtualize the RAN but to run AI and Data science processing at the Edge and RAN itself .

Having said this the hardware profile standardization of Open RAN components is already in full momentum with first release Beta coming in 2020 Feb and we expect to have a GA offer ready by end of 2020. So we can expect a commercial ready and GA  solutions of Open RAN to be ready by Q1 2021 .

Cost Efficiency of Open RAN and 5G Transport Networks

Although operators have gained early experience with 5G but obviously the cost to deploy the networks is quite high , it is primarily that still the RAN networks are not fully virtualized making transmission options possible that require a lot of transmission over heads . For example, based on our trials in middle East most vendors are coming with C-RAN delivery models only supporting Option 2-4 which waster more than 20% of transmission sources. Open RAN will make it possible to apply Option-7 to split the resources at RF and Lower Physical layers . The Open RAN lead network trails  will enable Cross-Layer network modeling to assess various scenarios

Understanding O-RAN , Open RAN , 3GPP

In the recent workshops with customers I have seen even a senior engineers sometimes confuse O-RAN , Open RAN and 3GPP itself , one common example is when some RAN teams claim that O-RAN is not 3GPP compliance and vice versa which obviously is  a wrong comparison  so it is important to share some thoughts of  how exactly it works

O-RAN:

As a matter of principle every O-RAN divides the whole RAN architecture in in RT-RIC (Real time  -RAN intelligent controller) , O-CU-CP(Open RAN CU control) , O-CU-IP (Open RAN CU user),O-DU (Open RAN DU) and O-RU (Open RAN RU) , the whole system view interconnected by interfaces is as follows

Source: O-RAN alliance

A1:The interface between RIC elements primary for policy control and implement AI/ML at the RAN side

O1:The O&M and monitoring interface

O2:The interface through which Orchestration layer control and provision the RAN Cloud components

E2 Interface:The interface that connects all the E2 nodes to the RT RIC , these E2 Nodes cane be CU-CP ,CU-UP ,DU or even an 4G O-eNb . As CUs are placed between RIC and DU, the location of CU will be left for decision of RAN vendors – either co-located with RIC or co-located with DU. Such choice will be an important for both telcos and vendors along the choice of open fronthaul. What is your choice?

Open Front Haul Interface:The interface between DU and RU

3GPP and its relation with O-RAN:

Primary body who defined the System Architecture and interfaces for horizontal services integration and specifications. 3GPP also defines a number of interfaces in O-RAN starting from 3GPP Release 15 where a nice description of interfaces can be found in 3GPP TS 31.905

The following interfaces are defined and managed by 3GPP and O-RAN is fully aligned with it as user or consumer of these interfaces these are

1. EI
2. FI
3. NG
4. X2
5. Xn
6. Uu

Open RAN:

Open RAN which is a TIP lead initiative is the complete E2E validation of O-RAN defined RAN architecture that also includes other components like Cloud ,Orchestration , Testing and validation of the full stack  The details can be found here https://telecominfraproject.com/openran/

“Open RAN Project Group is an initiative to define and build RAN solutions using a general purpose vendor neutral hardware and software defined technology “.

The flexibility of multivendor solutions enables a diverse ecosystem for operators to choose best-of-breed options for their 2G/3G/4G and 5G deployments. Solutions can be implemented on bare metal as well as on virtualized or containerized platforms.

One of the most important direction for Open RAN is to cover all 2G ,3G,4G and 5G NR solutions. Seeing Market in middle east as many operators will shutdown 2G by 2022 it is important specially to look for Open RAN solutions for 5G and 4G and in cases with 3G networks. Such pilots and network blue printing will be vital when we need to deploy such solutions in the brown fields.

In addition it will make possible for co-deployment and re-use of scarce spectrum resource’s between all access technologies.

RIC and Deployment Blue Prints for Open RAN Deployments

RAN intelligent controller (RIC) provides an interface between the RAN controller at the 5G core and the access network, enabling policy-driven closed-loop automation. The RIC is the interface piece that concatenates the RU, DU, and CU into the Open RAN (Full Functional Solution) through software programming and agile service delivery.

Introduction of many horizontal as well as vertical interfaces means more complexity to deploy and manage the Open RAN networks which requires a standard blue print manner to deploy such networks as provided by the Linux foundation Akraino Stack by abstracting the Infrastructure as a standard API and to be available Via standard API’s that can be consume d by the upper layers .RIC as depicted below deploy an east and flexible way to MANAGE Open RAN and having following characteristics

• Built from reusable components of the “Telco Appliance” blueprint family
• Automated Continuous Deployment pipeline testing the full software stack (bottom to top, from firmware up to and including application) simultaneously on chassis based extended environmental range servers and commodity datacenter servers
• Integrated with Regional Controller (Akraino Feature Project) for “zero touch” deployment of REC to edge sites

Orchestration of Open RAN

O-RAN Physical NF and O-Cloud represented by O-RAN architecture depicts the future RAN network comprise of many NE’s (As VNF’s or CNF’s) that will be part of standard Cloud -Cloud to be deployed on an X-86 hardware. This hardware will have standard acceleration support as may be required by each f the RAN NF and is responsible to de-couple each layer of the hardware from the software. However such a solution not only require standard deployment like Akraino but complete orchestration for both Day1 and Day 2 as supported by ICN (integrated Cloud Native network) . The standard orchestration is a key as it will not only orchestrate RAN functions but also other Functions like 5G CN along with provision of E2E Network slices and services.As the future Disaggregated networks split network in to layers so from both business perspective and technology view point we need to common set of tools to orchestrate the whole solution thus ensuring we  can provision any 5G and future business cases on the fly ranging from Remote Factory , e-health , video streaming , VGS broadcast etc .The latest Guilin release already consider how ONAP will power the Open RAN networks with future enhancement like REC blueprint automation and validation ,testing , FCAPS and running ML/AI streams based on Radio Network information are the features coming in next Honolulu release .

Summary

In summary O-RAN and related Open RAN solutions offer new architecture solutions for Telco industry that will make the Full disaggregation of networks possible. In addition to its alignment with Cloud and other related SDO’s mean the future networks can be al define, managed and operated suing same principles. For example, disaggregation means real value coming from deployment of singe transport infrastructure like IPV6 SRV+ where we can divide the single physical network in many logical networks that can serve both existing and new verticals. Similarly, Akraino /StarlingX and Airship installers will offer opportunity to deploy all stack using same principle and blue prints. Finally use of common orchestration platforms and futuristic networking slicing capabilities will open new business opportunities for Telco’s that was not possible before.

As we understand the overall mobility market is changing and coexistence of many access technologies including Wifi means dis aggregated , resource sharing and validated design is the need of the hour .It will not only help us unify the RAN but enable to really monetize the data from RAN like through AI and ML processing . It will also be fully beneficial for industry as a whole as fully open interfaces means  we can expand different components independently and validate it using open tools .s

This is therefore an important era to start the Open RAN journey and to take the early mover advantage in Disrupting the Networks  

Source: Linux Foundation

References:

1. https://www.5gtechnologyworld.com/5g-breaks-from-proprietary-systems-embraces-open-source-rans/
2. ONAP Guilin Release
3. Thought leadership recipes from Alex Jing
4. Akraino integrated cloud-native icn blueprint
5. https://docs.o-ran-sc.org/en/latest/architecture/architecture.html
6. Core analysis blogs