How far we have come from two-wire analog Plain Old Telephone Systems (POTS) lines to modern methods of communications. While two-wire POTS lines have mostly been repurposed to permit DSL connectivity, the time, effort, and expense seem to be keeping a dying horse alive with an IV. Present day levels of technology do not let wired phone lines compete with bandwidths and data.
Coax for cable TV went digital and provides good performance for HD TV as well as high-speed internet, and is the most deployed in a home, shared-media (TV, Phone, and Internet) connection. But, since the last mile (switching station connectivity to individual homes), is now using fiber, the higher bandwidth allows multiple devices to stream, search, and play simultaneously. This allows higher speed bi-directional communications to connect to in-home or in-building LANs and wireless links such as WiFi.
One important thing to note is that there is no such thing as a 100 percent fiber optic network. Every signal transits through routers, switches, hubs, and transceivers. These are copper and silicon.
Fiber does offer the highest potential speed in and out of a facility. But most data use is mobile and not plugged into any physical connection, meaning that our existing cellular 3G and 4G services, as well as WiFi have been the key players thus far. This is changing rapidly as new and advanced technologies bear down on the emerging 5G networks providing higher and higher levels of performance, features, and benefits.
One area of rapid advancements which will allow 5G technology to be massively deployed on a cellular level as well as for in-building use is the advancements in antenna design and deployment. Specifically, Multiple Input and Multiple Output (MIMO) antennas allow several frequencies and even bands, to share wireless connectivity as input only, output only, and bidirectionally. While this arrangement has been used with earlier generations, modern incarnations are improving on it by using large antenna arrays to multiplex many terminals and devices spatially.
Each antenna has its digital baseband chain, and coherent processing at each base station allows the fully digital processing system to offer better performance at lower energy. Another benefit is the elimination of the need for prior structural knowledge of the propagation channel. Instead, the reciprocity of propagation and the TDD operations hardens the channels. Here, the effects of fast fading are reduced with constant gain stabilized deterministic frequency independent performance.
In addition, a benefit of 5G is better network performance. Fewer compute resources are needed to encode/decode packets. This can reduce lag time and latency, which are responsible for annoying digital delay. It also provides uniformly good quality of service to all terminal in a cell’s reach.
The Orthogonal Frequency Division Multiplexed modulation techniques used with 5G allow 5G antenna design for large scale MIMO. A single carrier transmissions node, like an in-building router and gateway can take advantage of modern conjugate beamforming to create low cost well performing network antennas on a large scale (See Fig. 1).
Fig. 1. Higher frequencies mean shorter wavelengths which mean antenna arrays can be more easily and affordably produced to improve wireless and cellular services over more extensive areas for less money.
Another reason that 5G in-building systems are potentially superior to combined 4G and WiFi, is the availability of local and remote connectivity options. Cloud-based Radio Access Networks (C-RAN) is a proposed architecture for future cellular networks based on a centralized cloud-based architecture. It touts support for 2G, 3G, 4G, as well as 5G and future standards.
While fiber and WiFi are serving customers for most present needs, a unified 5G network can supplant the need for any physical connectivity to the internet and communications backbone. Instead of WiFi routers, we may have 5G base stations in our attics or computer rooms. Instead of paying for home telephone, cable TV, internet, and cell phone, one 5G service may be all we need.
When designing a 5G network, considerations for network density and network architecture can increase the sheer scope of design and implementation of 5G in-building networks. For a detailed view of the key technologies that might have the biggest impact on in-building networks and the basics behind each technology download the white paper written by iBwave’s Research Director Vladan Jevremovic- In-Building Network Evolution: From 4G to 5G
