# How Reliable and Capable is Multi-Connectivity?

## TL;DR

This paper develops an analytical framework to evaluate multi-connectivity in 5G networks, demonstrating its advantages over single-connectivity in reliability and data rates through theoretical analysis and real-world data.

## Contribution

It introduces a simple, accurate high-SNR analytical model for MCo, deriving exact outage coding gain, SNR improvements, and comparing combining algorithms.

## Key findings

- MCo offers significant SNR gain over SCo.
- Analytical framework matches real field measurements.
- Optimal combining algorithms outperform suboptimal ones.

## Abstract

Multi-connectivity (MCo) is considered to be a key strategy for enabling reliable transmissions and enhanced data rates in fifth-generation mobile networks, as it provides multiple links from source to destination. In this work, we quantify the communication performance of MCo in terms of outage probability and throughput. For doing so, we establish a simple, yet accurate analytical framework at high signal-to-noise ratio (SNR), in which the number of links, the spectral efficiency, the path loss, and the SNR are incorporated, giving new insights into the potentials of MCo as compared with single-connectivity (SCo). These are our main contributions: (1) finding the exact coding gain of the outage probability for parallel block-fading channels; (2) quantifying the performance improvement of MCo over SCo in terms of SNR gain; and (3) comparing optimal and suboptimal combining algorithms for MCo at the receiver side, namely joint decoding, selection combining, and maximal-ratio combining, also in terms of SNR gain. Additionally, we apply our analytical framework to real field channel measurements and thereby illustrate the potential of MCo to achieve high reliability and high data rates in real cellular networks.