5G represents an end-to-end change, as did 4G
When 4G was introduced, all parts of the network were transformed. A new 4G overlay network complemented the 2G and 3G networks. Mobile phones, radio, backhaul, and core networks went through a large change. The prediction for 5G is we will see a similar large shift across all areas calling for an end-to-end network strategy approach when planning for 5G.
The five major 4G transitions
When introducing 4G, the multiple 3G networking tracks, that is CDMA and WCDMA, merged into a common LTE track. 4G networks were built out as an overlay to 2G and 3G. The 4G market was shaped by network operators, network vendors, and terminal providers as for 2G and 3G. All changes introduced with 4G came with one big network bang, for example LTE radio, Ethernet backhaul and enhanced packet core.
Mobile phones moved from a communication-centric device to a multi-purpose smart personal companion. Despite strong initial hope for laptops as a driving device, it was the app-enabled smart phone that became the killer device. Consumer devices dominate for 4G.
The 4G radio agenda saw a global support for LTE as the technology of choice. Almost directly out of the gate, we saw a rapid increase in spectrum and band plan variants. 4G adoption rates and usage patterns varied between different regions quite substantially – where some markets are approaching 4G saturation now, others are still in ramp-up.
The 4G backhaul represented a big shift from leased or self-built TDM links in the Nx1.5-2Mbps range to Ethernet backhaul. The building pace demanded often created a high dependency of leased Ethernet circuits and a diverse provider base. It is today common to see a mobile network provider relying on leased circuits from telcos, cable operators, or local Ethernet service providers to support the full geographical reach of their network. 100Mbps has been a typical backhaul capacity.
The 4G packet core network went through a large shift compared to 4G. The architecture for 4G enhanced packet core was a major simplification and a large step towards powerful packet core networks where data was the primary driver.
The fifth major 4G innovation is tied to the delivery of voice. 4G is defined as a pure data solution without any circuit switched component. After an initial uncertainty, the mobile industry settled around VoLTE as the packet provided communication service for 4G.
What will remain and what will be different for 5G
5G has clear commonalities with 4G, in the sense that you need to consider the shift as an end-to-end challenge. The changes for each of the areas when we move to 5G are significant across all areas. 5G is likely to be introduced as an overlay to existing mobile networks. It represents a very large capability shift, with multiple parameters improving with 1-2 orders of magnitude compared to 4G. The 5G introduction will be less of a big bang, with introduction of 5G-ready elements as steps along the journey. The standardization work for 5G will have more influencing bodies than in the past.
At the device end we will see a broader spectrum of devices, and represent a mix between consumer and business specific devices. The biggest shift at the device end is the variety of industries we can expect to shape the ecosystem at the use-end and the fact we can expect to see devices being large consumers of data as well as sensors being large generators of data at the user end.
The 5G radio capabilities have gotten the lion-share of the initial attention. Perhaps the biggest change is the introduction of spectrum an order of magnitude higher up , which calls for radios closer to the users. Small cells, centralized basebands, densified 4G grids, integration of WiFi and 5G all represent a new radio reality.
With an expectation of 10-100X improvements in certain characteristics, the current backhaul paradigm is running out of steam. 5G will require an uplift to the 1Gbps range with a smooth migration to 10Gbps per radio site. The radio variety will be supported with a combination of front-haul and backhaul solutions. Alternative fiber solutions and business models will be explored.
The packet core network shifts are perhaps the least explored. The 5G traffic patterns will shift substantially, calling for both topology and architecture shifts. Core networks are in the middle of a virtualization journey for 4G capabilities with 5G to follow soon.
Predictions for the near term future
- 5G networks will be approached as a new end-to-end networking challenge.
- The 5G network standardization will build on the best from multiple different industry paradigms.
- The earlier the deployment is scheduled, the more important it will be to target a holistic solution.