RADIO ON RADIO OVER FIBER EFFICIENT FRONTHAULING

FOR SMALL CELLS AND MOVING CELLS

Wireless CommunicationSUBMITTED BY Mafaz Ahmed 1882-FET/BSEE/F12

IntroductionRadio On Radio Over Fiber means the combination of radio-link and fiber link (for mobile signal transmission)A combination of fiber and radio links based on photonics technologies are used to generate and transmit radio wave signals

Fronthauling

Fronthaul is the connection between a centralized Base Band Unit (BBU) and remote standalone radio cells (Nodes)

This is a high-speed and low-latency transmission links

Remote Radio Head (RRH) & Remote Antenna Unit (RAU) Remote Radio Head &  Remote Antenna Unit

are remote radio transceivers used to connects to an operator radio control panel via electrical or wireless interface

At RAUs, the optical signal is converted to a wireless or electrical signal

At remote radio heads (RRHs), the received wireless or electrical signal is converted back to mobile signal

FIBER AND RADIOWAVECOMBINATIONSa: conventional optical-mmWave link; b seamless optical and mmWave connection;

c: analog radio on a seamless optical-mmWave system.

FIBER AND RADIOWAVECOMBINATIONS Conventional System of Fig 1.a is complicated, high cost, high

power consumption, and long transmission delay System of Fig 1.b RAUs to be very simple, but system require

high bandwidth requirement, signal synchronization needs, high jitter, and long latency

System of Fig 1.c is more suitable, especially for small-cell based networks because of Analog waveform transmission of mobile signals require low bandwidth. Simplifies the RAUs and RRHs, and considerably reduce the cost, power consumption, and latency compared to the conventional systems

APPLICATIONS TO FRONTHAUL NETWORKS

Important application of the system is to provide broadband connections to moving cells, such as on fast-moving trains

Several RAUs can be located along the railway track and connected to the CSs by fiber cables. RRHs can be installed on the trains to communicate directly with users. Antenna units on the trains (TAUs) can receive and transmit mmWave signals from/to RAUs.

By this method, it is possible to send the same signals to the trains, even when the train moves to a new RAU. A real handover procedure will be needed when the trains move to a RAU that is controlled by another CS.

Moving cells

APPLICATIONS TO FRONTHAUL NETWORKS

A seamless combination of fiber optic and radio systems is particularly suitable for deployment of ultra-dense small cells, especially in areas where the use of fiber cables is not feasible

The frequency range from 70 to 110 GHz (E- and W-bands) is suitable for applications to fronthaul networks because of its small atmospheric attenuation

To compensate for high free space loss in the mmWave bands, highly directive and high gain antennas are used

Small cells

APPLICATIONS TO FRONTHAUL NETWORKS

Moving cellsSmall cells

ADVANTAGES OF THE SYSTEM

Scalability Latency Power consumption Handover Centralized management

CHALLENGES AND PERSPECTIVE

High-performance system

Ultra-dense small cells

Multiple-input multiple-output (MIMO) signal

transmission

The End