As commercial 5G deployments at scale become more a question of “when” rather than “if”, the industry is taking a more holistic view of 5G transport requirements.
Even as capacity requirements have increased exponentially with each successive mobile technology generation, mobile backhaul has typically been a relatively straightforward proposition. Take the traffic from the RAN and deliver it to the mobile core. As operators prepare to deploy 5G in a meaningful way, they are finding the need to fundamentally rethink their mobile 5G transport strategies.
At a very high level, mobile transport is no longer simply about backhaul. To borrow a phrase from Nokia, it is about “anyhaul”, meaning fronthaul, backhaul, even “midhaul” in certain places. Of course, all of the major mobile equipment vendors have been on record with solutions aimed at 5G transport for a few years now. Ericsson has, arguably, been one of the more aggressive suppliers in articulating its 5G transport vision, but Huawei, Nokia, ZTE also have a full library of solution literature as do leading optical suppliers such as Ciena, Cisco, Coriant/Infinera, etc.
It’s more complex, but how?
As opposed to previous generations of mobile transport development 5G will add several new vectors of complexity that were not front and center issues as mobile networks developed from 2G to 3G to 4G/LTE. It would be easy enough to point to IoT as a leading driver in the increase in complexity, but the true reason(s) are both more fundamental and complex. The heart of the issue is that since 5G is more than a new mobile network generation, the diversity of applications a true 5G network must support go well beyond mobile (though, in true chicken and egg fashion, the rub is that most all of the vast ecosystem of 5G applications will have a mobility component). As more applications begin to leverage a 5G network, as opposed to just a fixed network, or just a mobile network, or just an enterprise network, the number of applications that will compete for resources will increase dramatically.
To this end, the vectors that will now play a key role in the design of 5G transport networks can be summarized into 4 high-level categories:
Capacity – as gigabit mobile and/or fixed wireless connections become the norm, the capacity requirements for mobile transport networks will increase exponentially. This will require an “all hands on deck” approach to delivering the capacity required to satisfy the demands of the new and varied applications that will demand capacity resources in a 5G environment.
Performance – as mentioned above, with 5G, multiple applications will be competing for network resources. These will be varied from ultra-low latency applications related to advanced IoT (think driverless cars), to mission critical public safety applications, to high bandwidth consumer applications like AR/VR, streaming media, gaming, all the way down to sensors in a home automation environment pinging each other. The ability to monitor the performance requirements and prioritize access to backhaul links will be vital to success. This means that 5G transport is going to be as much about the service monitoring solutions involved as it will be about the physical media that the traffic travels over.
Latency – Hand-in-glove with 5G network performance is latency. As multi-edge computing solutions help to push core network resources closer to the user the ability of the transport network to keep pace, and not become a bottleneck will be key. In this regard, while fiber will be a big part of the solution, it is overly simplistic to think that more fiber, by itself, will be sufficient. Fiber is not ubiquitous, so gigabit microwave will be required. Copper-based solutions can play a role. And, even where fiber is available, span distances will require inventive solutions to ensure that latency requirements can be met.
Security – Naturally, as the scope of different solutions increases, so will the security precautions that will need to be considered. Here is where IoT will become a factor. As with most other parts of an IoT network, the increased number of potential access points will create new opportunities to attack the transport network. Similarly, as the diversity of applications running over a 5G network increase – many of which will carry life and death implications – the need to secure the transport links becomes as vital as securing the RAN and core.
