Advantages of Sub-6 GHz 5G | disadvantages of Sub-6 GHz 5G

This page covers advantages and disadvantages of Sub-6 GHz 5G network over mmwave 5G network. It mentions benefits or advantages of Sub-6 GHz 5G and drawbacks or disadvantages of Sub-6 GHz 5G.

What is Sub-6 GHz 5G?

Introduction:
Wireless operators have been deploying 5G networks since 2019. It follows 3GPP release-15 and above specifications. The main use cases of 5G technology are eMBB, mMTC and URLLC. Collectively they are known as "5G Vision". mMTC is used for long battery life and device density requirements, uRLLC is used for low latency and high reliability requirements and eMMB is used for faster data rates and higher spectral efficiency requirements.

The figure depicts typical 5G network consisting of gNB (i.e. gNodeB or Base Station), 5G small cells and 5G mobile phones. 5G network can be deployed in two modes viz. non-standalone (NSA) and standalone (SA). In NSA mode, it works with LTE network in which control signaling is handled by LTE where as data part is handled by 5G NR system. In SA mode, both control signaling and data signaling are handled by 5G system and it works independent of LTE network system.

There are two frequency bands designated in 5G NR system viz. FR2 and FR1. FR2 uses mmwave frequencies comprised of "high band" frequencies. FR1 uses sub-6 GHz frequencies comprised of "low band" and "mid band" frequencies.

Benefits or advantages of Sub-6 GHz 5G

Following are the benefits or advantages of Sub-6 GHz 5G:
➨The path loss of transmitted signal is less than mmwave frequencies.
➨The sub-6 GHz frequency waves incur lower penetration losses than mmwave. Hence it is ideal to deploy 5G network in large urban areas.
➨Sub-6 GHz networks use MIMO at transmitters and receivers which results into more robust signals and higher SNRs. Hence higher signal data rates can be achieved.
➨Due to longer wavelengths sub-6 GHz signals undergo more transmission reflections than mmwave signals. This offers advantages due to use of MIMO.
➨Channel State Information (CSI) is used to maintain optimized wireless link. Parameters such as scattering, fading, path loss, blocking etc. are repeatable at sub-6 GHz frequency range. This provides more favourable environment for signal propagation.

Drawbacks or disadvantages of Sub-6 GHz 5G

Following are the drawbacks or disadvantages of Sub-6 GHz 5G:
➨It uses multiple bands, multiple standards, CA (Carrier Aggregation) and dual connectivity (LTE/5G). This makes implementation complex and makes system expensive.