5G Software Architecture

Previously, we’ve looked at the hardware requirements of 5G. This week, we will take a look at the software infrastructure targeted for 5G deployments. There are published concepts and specifications by vendors like Intel and standards organizations such as O-RAN and OpenRAN. However these concepts are a bit nebulous, and these concepts may not work with all the potential use cases of future 5G deployment. Many of these concept and specs are focused on carrier grade deployments, and there are many potential 5G customers outside of telecom applications such as manufacturing campus or huge vessels.

There is a common trend among the different designs: the software stack is going away from bare-metal and moving towards virtualization or containerized software stack with centralized management software to easily deploy and manage all the nodes. Solutions from RedHat, VMware, and other leading software vendors all coming with VM and container management solution that can host customized 5G software stack. Intel is in on the action as well with the virtualized FlexRAN solution. The aim of these software stack is chaining together a cohesive stack of centrally managed software.

One of the leading VM software suite vendor, VMware, is integrating container support into their vSphere virtualization platform, showing how the container concept is catching on and can no longer be ignored by virtualization specialists. Red Hat, another juggernaut in enterprise OS and virtualization platforms introduced OpenShift container management platform. Even Microsoft got in on the container band wagon, integrating OpenShift into their Azure hybrid cloud computing platform.

For those with limited scale or budgets, Docker containers deployed through Kubernetes orchestration system are available freely. These open source alternatives don’t give up on features. The biggest difference, as usual in the open source landscape, is support. Professional support is available from the boxed software vendors, where as in open source alternative you will rely on documentations and community support for debugging issues that may arise.

The software stack is paramount moving away from proprietary vendor solutions and towards open standards software and hardware. This will bring down the hurdle for enterprises and business who wish to build private 5G networks for their internal needs. This allows open competition on the hardware front. It is great for hardware vendors, despite the increased competition. It forces vendors to innovate to attract customers as well as building on their own vision of 5G hardware to carve out specific niche markets. One size fits none and through the competition, it will allow customers to find hardware that fits their exact needs and choose software that will integrate well into their existing software infrastructure. What we’re envisioning is enterprises will choose to run a base OS they’re familiar with, such as RHEL or CentOS, then run a vendor provided KVM or, more likely, containers that bundles all the software required. Software and hardware vendors will need to work closely to provide application optimized solutions.

Thanks for joining us again for another look at 5G. We’ll revisit this topic as industry trends becomes more concrete. All-in-one small-cell looks like the next hot 5G topic, and we’ll definitely look deeper into that in a future blog post.

這篇文章 5g Software Architecture 最早出現於 AEWIN。

5G软件架构

此前，我们已经研究了5G的硬件需求。本周，我们将了解面向5G部署的软件基础设施。英特尔等供应商以及O-RAN和OpenRAN等标准组织发布了一些概念和规范。然而，这些概念有点模糊，这些概念可能不适用于未来5G部署的所有潜在用例。其中许多概念和规范都侧重于运营商级部署，并且在制造园区或大型船舶等电信应用之外还有许多潜在的5G客户。

在不同的设计中有一个共同的趋势：软件堆栈正在远离裸机，转向虚拟化或容器化的软件堆栈，使用集中式管理软件轻松部署和管理所有节点。RedHat、VMware和其他领先软件供应商的解决方案都附带了VM和容器管理解决方案，可以托管定制的5G软件堆栈。Intel®也加入了虚拟化FlexRAN解决方案的行列。这些软件堆栈的目的是将集中管理的软件的内聚堆栈链接在一起。

领先的VM软件套件供应商之一VMware正在将容器支持集成到其vSphere虚拟化平台中，展示了容器概念是如何流行起来的，并且虚拟化专家再也不能忽视它。企业操作系统和虚拟化平台的另一巨头红帽公司推出了OpenShift容器管理平台。甚至微软也加入了容器潮流，将OpenShift集成到他们的Azure混合云计算平台中。

对于那些规模或预算有限的用户，可以免费使用通过Kubernetes编排系统部署的Docker容器。这些开源替代方案不会放弃功能。与开源领域一样，最大的区别在于支持。专业支持可从盒装软件供应商处获得，在开源替代方案中，您将依赖文档和社区支持来解决可能出现的调试问题。

软件堆栈最重要的是从专有供应商解决方案转向开放标准软件和硬件。这将为希望为内部需求构建私有5G网络的企业和企业降低障碍。这允许在硬件方面进行公开竞争。尽管竞争加剧，但这对硬件供应商来说是一件好事。它迫使供应商进行创新以吸引客户，并建立自己的 5G 硬件愿景以开拓特定的利基市场。一刀切，通过竞争，客户将能够找到满足其确切需求的硬件，并选择能够很好地集成到其现有软件基础架构中的软件。我们设想的是企业将选择运行他们熟悉的基础操作系统，例如 RHEL 或 CentOS，然后运行供应商提供的 KVM，或者更有可能是捆绑所有所需软件的容器。软件和硬件供应商将需要密切合作以提供应用优化的解决方案。

感谢您再次加入我们，再次了解 5G。随着行业趋势变得更加具体，我们将重新讨论这个话题。一体化小型基站看起来像是下一个热门的 5G 话题，我们肯定会在以后的博文中对此进行更深入的研究。

這篇文章 5G软件架构 最早出現於 AEWIN。

O-RAN, OpenRAN, and OTII, are the 3 most prominent specifications published so far and each has high profile members. We’ll look into each from the perspective of RAN hardware design considerations for 5G private enterprise networks and highlight some key specs and compare them as we go through the specs.

O-RAN published specs: https://www.o-ran.org/specifications

O-RAN by the O-RAN Alliance, favored by many major telecom operators, such as AT&T, Verizon, T-Mobile, Sprint, Orange, Vodaphone, NTT Docomo and more. It envisions the 5G network broken down into RU feeding to DU (distributed units) and then up stream to CU (central units) which then feeds into the core network. Due to the telecom focus, it defined a wide temperature range of -5~55C typical for equipment for this sector. This is a departure for most data center oriented manufacturers who typically does not validate against such high temperature. Another notable change is -48v DC power input. Hyperscalers has been moving towards DC in a bid to reduce inefficiencies of AC/DC conversions, so many manufacturers already have experience dealing with DC power. This should be just validation of CRPS -48v DC PSU with power cables rated for the increased current. In a move that would make many typical server manufacturers unhappy, it defined the chassis depth to <750mm. Not very far from off the shelf servers, but it still requires change of design and tooling to fit into the specified depth along with the associated cost of validating a new platform. Overall, this is very telecom focused specs. It remains to be seen that whether or not enterprises will request hardware that strictly follows this spec.

OTII published specs: http://www.opendatacenter.cn/work-group/p-1143085492931629057.html

OTII is published by the Chinese Open Data Center Committee with aim to use whitebox servers for the 5G network infrastructure. It is initiated by 3 major Chinese telecoms: China Mobile, China Telecom, and China Unicom along with Intel and CAIST. These 3 telecoms are also members of O-RAN. OTII specs departs from the others with its more modest temperature range requirement of 5~40C (-5~45C short term). This spec does not meet the minimum requirements for western telecoms or NEBS, therefore OTII is unlikely to gain traction outside of China even though this may be a more realistic operating environment for these equipment. It also has restrictive 450mm chassis depth requirement (specifying 2U for to fit all the required components). This lowers compute density and appears to be bespoke for the participating telecoms. Spec compliant servers are already being delivered, and likely be the largest current deployment for the 3 specifications today. The fast deployment is likely due to the specs defined by the telecoms themselves and as mentioned above, likely bespoke for their environment to allow the fast deployment of these servers to meet the aggressive 5G rollout schedule.

TIP – OpenRAN: https://telecominfraproject.com/openran/

Telecom Infrastructure Project defined a competing RAN specification. It is an open project and free to join as opposed to O-RAN’s paid membership, allowing it to gather a sizable membership. To note, many prominent members of OpenRAN are also O-RAN members.The specs are still in the early stages with tentative published specs. Out of the 3 specs today, this is the most incomplete with some DU specs defined and very little of CU specs. There are also some oddities inside the specs. For the power requirements, it defined -48v DC like the O-RAN spec, however it added 110v AC as well. Very odd to include only 110v but not 220v that is more common for data centers and majority of European countries. It also required -40~55C operating range for the DU. -40C low temperature range will be a harsh spec for manufacturers, requiring heaters to avoid low temperature issues. OpenRAN seems to picture that DU will be exterior pole mounted along with the RU, exposing the system to the weather extremes. The specification should be separated into interior and exterior mounted systems, as making a single system to serve both environments will drive up cost needlessly.

Here is chart that summarize the important specs from each:

There are a lot of similar concepts shared by all 3 specifications. On the power side, all have specified telecom focused -48v inputs. This makes sense as the specs are heavily telecom focused and it is a standard for the industry. However, OTII has included 220/110VAC support to allow more flexibility of placement due to the ubiquity of AC power. It will allow placement outside of telecom operator controlled locations or where it may be financially inadvisable to add -48v DC power.

For the physical form factor, all of them have specified shorter depth of the chassis. However only OTII have specified system that will fit into standard 600mm depth telecom racks. OTII did get a little too ambitious on the depth, which will limit the versatility of the system for other applications. We believe chassis depth of around just under 600mm is probably the most versatile along with front access design for ease of service and thermal consideration. This size will be big enough to pack in enough features and compute density but small enough for majority of deployments. Of course, physical sizes are highly dependent on end customer’s location for the deployment. This is probably where most obvious segmentation happens in the overall hardware landscape, and where manufacturers can differentiate themselves by choose the right size vs feature set.

Thanks for joining us for a quick look at the 3 main specifications for 5G RAN architecture. As the specifications mature, we’ll definitely revisit and do some more comparison in the future.

這篇文章 A look into published 5G vRAN specs 最早出現於 AEWIN。