This document discusses radio on radio over fiber (RoRoF) fronthauling for efficient transmission of mobile signals in small cells and moving cells. RoRoF uses a combination of fiber and radio links, where optical signals are converted to radio signals and vice versa. This allows analog radio signals to be transmitted over fiber with low bandwidth and latency requirements. Key applications are providing connectivity to fast moving trains and deploying ultra-dense small cells where fiber is not feasible. The system offers advantages of scalability, low latency, power efficiency and centralized management. Challenges include developing high performance systems for MIMO transmission in ultra-dense small cell environments.

1. RADIO ON RADIO OVER FIBER EFFICIENT
FRONTHAULING FOR SMALL CELLS AND
MOVING CELLS
Wireless Communication
SUBMITTED BY
Mafaz Ahmed 1882-FET/BSEE/F12

2. Introduction
Radio 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

3. 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

4. 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

5. FIBER AND RADIOWAVECOMBINATIONS
a: conventional optical-mmWave link; b seamless optical and mmWave connection;
c: analog radio on a seamless optical-mmWave system.

6. 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

7. 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

8. 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

9. APPLICATIONS TO FRONTHAUL NETWORKS
Moving cellsSmall cells

10. ADVANTAGES OF THE SYSTEM
 Scalability
 Latency
 Power consumption
 Handover
 Centralized management

11. CHALLENGES AND PERSPECTIVE
 High-performance system
 Ultra-dense small cells
 Multiple-input multiple-output (MIMO) signal transmission

12. The End