Home » Proposal » Radio over fiber thesis proposal

Radio over fiber thesis proposal

Radio over fiber thesis proposal To increase

Our Guarantees Our Quality Standards Our Fair Use Policy

Why Is United kingdom Essays Different?

  • There exists a verifiable buying and selling history like a United kingdom registered company (details at the end of each and every page).
  • Our Nottingham offices are available to the general public where one can meet we well over 40 full-time staff.
  • United kingdom Essays partner with Feefo.com to write verified customer testimonials – both negative and positive!

Ask a specialist FREE

Ask a specialist Index Ask an issue Compensated Services

About Our Ask a specialist Service

Our free of charge “Ask a specialistInch Service enables users to obtain an answer as high as 300 words to the academic question.

  • Questions typically clarified within 24 hrs.
  • All solutions are researched and compiled by properly accredited academics within the question’s area of interest.
  • Our services are completely private, only the reply is printed – we never publish your individual details.
  • Each professional answer includes appropriate references.

About Us

Much More About Us

Printed: 23, March 2015

Abstract – To support high traffic demands and data rates, some solutions were suggested for example decrease in cell size and operating in new frequency bands. However these solutions have expense connected together. Next a brand new economical technology Radio over fiber (RoF) was suggested. It’s an integration of wireless and fiber optic technologies. Comparisons of various RoF technology is discussed using their benefits and drawbacks. RoF has benefits of large bandwidth, low power consumption, high reliability and security. It’s also disadvantages of chromatic and modal dispersion. Multiplexing techniques like Sub carrier and wave length division multiplexing can be used for RoF.

Radio over fiber thesis proposal Each professional answer comes

Network architectures for various applying RoF happen to be suggested. A few of these architectures are discussed for in building, rural areas, road vehicle systems and Reconfigurable RoF. RoF has applications in mobile systems, fixed systems and satellite communication systems.

Index Terms- Radio over fiber, Subcarrier multiplexing, exterior modulation, optical heterodyning, frequency up conversion, wave length division multiplexing, chromatic dispersion, modal dispersion.



Get the grade
or a refund
using our Essay Writing Service!

Essay Writing Service

At the begining of times of telecommunication, everyone was thinking about voice communication only. Speech signals use less bandwidth varies from 300 Hz to 3100 Hz.

GSM which was the important thing technology in those days, is incompetent at delivering high data rates. However with the passing of time people are not only seen restricted to low data rates. Now

they care more about broadband communication. Broad band communication is the necessity of the hour. With this particular, it isn’t just easy to send voice signals but additionally data signals and multimedia signals and interestingly simultaneously. Users are demanding services which will provide them a quicker transmission, flexible and anytime anywhere solutions. For instance, WiMax and WiMAN, use bandwidth as much as 1Gbps with wide coverage area. [1] Somewhere, wireless operators are facing challenges to supply such high data rates to users as well as on other part figures of users are growing daily.

Radio over fiber thesis proposal com to publish verified customer

Wireless operators are more and more challenged to support an excellent diversity of information oriented mobile services and also the growing quantity of finish users. [2] So an issue was elevated additional problem. To boost traffic capacity and users high data rates demand simultaneously is a huge problem. Some solutions were suggested with this problem. As you may know our conventional cell varies from 1-2Km. If cell dimensions are reduced as much as 300 meters then network may have many cells. Such many cells boosts the capacity. These small cells are referred to as pico cells or micro cells. But regrettably large figures of base stations are needed for this function. Such large base stations increases our network cost. Next upkeep of these base stations isn’t an easy task.

To resolve this issue a brand new technology was suggested that’s known as Radio over Fiber (RoF) technology. Suggested by its name it

is definitely an integration of Wireless and optical fiber technologies. To obtain the secret behind mixture of wireless and optical fiber, benefits and drawbacks of both technologies should be known. The greatest benefit of wireless includes mobility. This means transmitter and receiver can move about any place in the network but still in a position to avail all services provided by the network but growing quantity of users is a huge problem. Fiber however, has benefit of high capacity however it lacks mobility. Therefore the fundamental idea behind fraxel treatments is definitely an amalgamation of both wireless and fiber that can result in high data rate, high capacity and mobility solution.


RoF is definitely an analog technology. The fundamental principle behind RoF would be that the light signal is modulated through the radio signal. Radio signal is changed into optical signal. This will make it transmitted via optical fiber to receiver side. In the receiver, the optical signal is again changed into radio signal after which transmitted via air interface. Thus the connectivity between central station and base station is dependant on optical fiber and also the connectivity between base station and remote mobile unit is dependant on air. Figure 1 [1] is showing the machine topology for RoF system.

fig1: RoF system construct [1]



Always promptly
Marked to plain

In RoF there are various methods for signal generation and distribution. Included in this are:

Exterior modulation of continuous wave laser light within the central station [3]

Frequency Up conversion.

Intensity Modulation Direct Recognition (IMDD) may be the simplest technique. It’s further split into Direct Modulation and Exterior Modulation. IMDD can be used for low/medium RF range. Chromatic dispersion is a huge condition in IMDD. For the reason that of producing double side bands in the creation of modulator. If single side band modulation can be used this issue will be solved. To beat chromatic dispersion, some compensation methods may be used for example fiber Bragg grating. Figure 2. [1]

Fig 2. IM-DD Technique [1]

a)Directly modulated RF b) Externally modulated RF

Optical heterodyning is nice in this way that chromatic dispersion decreases however it has problem of phase noises. For the reason that the spectrum from the multiplexed signal lies not far from each other also it leads to Phase noise. To beat phase noise problem, a method Optical Injection Locking can be used.

Frequency Up conversion doesn’t need any modulator in the transmitter side however it requires top quality local oscillators for synchronization which boost the cost. Next high power is needed to transmit the information signal using the optical reference signal.


RoF technologies could be in contrast to each other. Different experiments were performed for this function. Outcomes of these experiments are summarized in Table 1 [4]

RoF has many advantages. It’s transparent to bandwidth and modulation techniques [4]

Large Bandwidth

For any single SMF optical fiber, the combined bandwidth from the three home windows is incorporated in the more than 50 THz [15].In existence of such high BW, we are able to transmit not just voice and knowledge signals but additionally video signals and interestingly each one of these formats on single fiber.

Centralized Network

RoF adopts a perception of centralized network. One central station (CS) is shared by many people remote antenna units (RAU). Consequently all signals processing and routing is conducted at CS with the result that size RAU has reduced. Thus it may be placed any place in the atmosphere. Cost connected with site acquisition, site leasing has additionally reduced.

Reduced Power Consumption

Conventionally, copper cables were utilised to give signals to antennas. These copper cables are extremely lossy anyway. Signal power reduces during its transmission from 3dB to 10dB transmitter to receiver. To improve the SNR, signal power is enhanced. High power amplifiers are needed for this function that is costly somewhere and fewer efficient on other part. Utilization of fiber optic rather of copper, leads to lossless transmission. No or fewer power losses so there aren’t any dependence on ac.

Low Attenuation

Fiber optics has very less attenuation. Because of fiber optic using repeaters also reduces. Transmission loss reduces from .3dB/Km to .5dB/Km.

High Immunity

It’s high immunity against mix talk which leads to secure and reliable transmission.

Dynamic Allocation of BW

There’s no dependence on static BW allocation. Control is centralized so every user is entertained based on the use. Thus have the ability to allocate the BW dynamically. Dynamic allocation is achieved by utilizing wave length division multiplexing (WDM)

Capacity Enhancement

Capacity from the product is elevated by utilizing RoF technology. For the reason that from the improvement in trunking efficiency. Through trunking network access is supplied to a lot of users by discussing group of lines or frequencies rather of allocating them individually.

High reliability

RoF provides high reliability and security. For the reason that of why fiber optics are constructed with insulators. Thus the optical signals don’t interact with any atmospheric constituents which leads to secure transmission.


This Essay is

This essay continues to be posted with a student. This isn’t a good example of the job compiled by our professional essay authors.

Types of our work

RoF has additionally some limitations.

Chromatic Dispersion

Optical fiber can be used for connecting CS with BS. Chromatic dispersion increases with the rise in fiber length. Because the fiber length increases, signal degrades and SNR reduces to undesirable level. Thus it’s not easy to introduce lengthy spacing between transmitter and receiver. This chromatic dispersion is connected using the single mode fiber.

Modal Dispersion

Multimode fiber can be used for brief distances. It’s problem of modal dispersion. To beat dispersion, some dispersion compensation methods are utilized however it can increase our network cost.


The laser is generally a significant supply of noise and distortion within an ROF link, and laser diode normally exhibits nonlinear behavior [3] Laser behaves non straight line when current is driven over the threshold value. This non-linearity causes noise with the result that dynamic range decreases.


Multiplexing is really a process where single medium is shared by many people users to improve the capability.

Sub-carrier Multiplexing (SCM) in RoF Systems

SCM is really a technique that enables different fiber optics signals to multiplex into single fiber. It’s a mature, easy and economical approach. Within this plan, different signals are modulated with various sub carriers. These modulated signals will be multiplexed. This multiplexed signal is again modulated. This signal will be transmitted to receiver. Benefit of SCM is it supports traffic of various modes.

Subcarriers are utilized within this technique. These sub carriers have low frequencies. For this reason their components are often available.

b) Wave length Division Multiplexing (WDM) in RoF Systems

WDM is definitely an analog multiplexing method to combine different wavelengths. An amalgamated signal is acquired after multiplexing that’s delivered to the receiver side after which Demultiplexer can be used to split up the composite signal into separate signals. The use of WDM in RoF systems has numerous advantages including simplification of network topology by allocating different wavelengths to individual BSs, enabling simpler network and repair upgrades and supplying simpler network management. Thus WDM in conjunction with optical mm-wave transport continues to be broadly studied. [5]- [8]

Dense Wave length Division Multiplexing (DWDM) can also be extensively using in RoF systems. Because of DWDM system capacity has elevated tremendously. Rather of four channels now system can hold 128 channels while funnel spacing has reduced from 500 GHz to 50 GHz. But there are several challenging issues related to this integration of RoF and WDM. Most significant is quantity of wavelengths which are needed for just one BS. Full duplex communication can be done if a person wave length can be used for downlink and uplink. However wave length reuse method has been suggested in [7] to resolve this issue.


Many Network architectures happen to be suggested for various applying RoF.

RoF based architecture for In-Building Systems

In [9], architecture was suggested for in-building systems. Within this architecture a brand new technique ‘Optical Frequency Multiplying’ (OFM) is implemented. For this reason technique you’ll be able to provide high capacity wireless services to users based on their requirements. This architecture is dependant on multimode fiber. Multimode fiber is simple to set up and economical however it has limitation of modal dispersion. Because of OFM you’ll be able to reduce modal dispersion. OFM assists you to use multimode fiber In- building.

Dynamic Capacity Allocation

For dynamic radio capacity allocation FBG based wavelengths add drop multiplexers were utilised to show the idea.

fig 3. Wave length routed radio over multimode fiber

(ADM- Add drop multiplexer, MMF- Multimode fiber, FBG – Fiber Bragg Grating)

ii) Results

For this function, multimode mode fiber of 50um was utilized. Three wavelengths were selected i.e. 1304, 1310 and 1315 nm. It had been implemented for ring topology.

Effective conversion and transport of RoF signals was achieved for 950 meters of silica graded index fiber. It had been achieved for RoF signals of 18.3 GHz that may carry data as much as 36 Mbits/s through the use of 16- QAM on 52 subcarriers of OFDM.

RoF based architecture for Road Vehicle Communication Systems

In [10], a method is suggested for road vehicles communication systems. To improve data rates, cell size continues to be reduced. This small cell size leads to high mobility. High mobility leads to many handoffs. Control over such system isn’t an easy task. So a Media Access Control (MAC) plan is suggested featuring fast handovers according to dynamic TDMA.

Media Access Control

This MAC protocol plan has benefits of quick and easy handovers. It’s also able to dynamic bandwidth allocation. Frame structure for MAC protocol is proven within the figure 4.

fig. 4 Frame Structure

Each frame is associated with a particular BS. Frame includes a beacon field. Seo contains BS identification number and slot assignment map indicating the beginning position of slot and it is length for every MH. After beacon field, it’s field of reservation minislots. It’s further split into minislots for give demands as well as for new connection demands. It’s utilized by individuals MH that have not reserved any slots however they have data to deliver. Then there’s broadcast field. Seo contains data about previous reservation trials. This information is broadcasted through seo. There are fields for downlink and uplink. Uplink also includes one bit handover indication flag for fast handover.

A MH first scans the RF channels. A request bandwidth is distributed towards the CS using reservation small-slots. If CS has enough bandwidth then it’s allotted to MH in next super frame.

Kinds of handovers

Various kinds of handovers are discussed with this architecture.

Intra-VCZ handover: Handover happens between two BSs. These BSs fit in with exactly the same VCZ.

Inter- VCZ handover: Handover happens between two BSs. These BSs fit in with different VCZ.

Inter- CS handover: Handover occurs between two BSs which are controlled by two different CS.

Figure 5 is showing illustration of suggested architecture. This architecture is composed of CS that is associated with five BSs. It’s two VCZ. Three kinds of handover will also be happening in cell phone number 2, 3 and 4. Cell 2 and three take part in intra- VCZ handover. Inter VCZ handover is happening between 3 and 4 cells. While cell phone number 4 and 5 take part in Inter – CS handover.

fig 5. A good example of the suggested architecture where cell 1,2,3 and 4,5 constitute VCZs (Virtual Cellular Zone) correspondingly


This architecture has limitation associated with resource allocation. To enhance the caliber of Service (QoS) effective handover management is essential. A guard funnel concept was suggested where some bandwidth is restricted to handovers. To suggest this idea for VCZ, some modifications are attempting to do. Using these modifications bandwidth is allotted to VCZ rather of every cell. Research efforts happen to be designed to solve this problem.

c) RoF based architecture for Rural Areas

In [11], radio over fiber based broadband wireless access network architecture is suggested for rural areas. Though cities will always be a warm place for communication but calls for services in rural areas are continuously growing. Tunable transmitters and tunable receivers are utilized within this system. However WDM can be used to improve the capability. All base stations are tuned to particular wavelengths for flexible bandwidth allocation. Capacity is restricted however the central station structure really is easy.

Architecture Description

This technique are operating in TDMA mode. Transceiver props up BS only when it knows the wave length and RF funnel utilized by the BS. The assumption is that RF channels happen to be based on BS. RF channels for every BS are fixed. This assignment is bound and according to frequency reuse technique. Observe that the bandwidth presented to any BS is restricted through the capacity from the TRX. Just one wave length is allotted to every BS to prevent wave length collision. This architecture has two silent features. First it offers flexible bandwidth allocation. Next, system capacity could be enhanced easily. For the reason that of why system capacity is directly proportional towards the TRXs. By growing quantity of TRXs, system capacity can elevated easily.

Fig6. A suggested radio over fiber access network architecture composed of K transceivers (TRXs) and N base stations (BSs)

To prevent collision, frames are fragmented in a way that no wave length collision can happen. For K TRX, K super frames are generated. There’s a scheduler at CS. This scheduler controls each TRX.

Fig7. Packing of 5 frames into two super frames


It’s limitation connected with dynamically altering bandwidth capacity of CS. CS can alter time and frequency bands anytime. It results in adjacent funnel interference because adjacent channels cannot use same frequencies simultaneously.

Reconfigurable Radio over Fiber (RoFnet)

In [12], a manuscript architecture is suggested. WDM can be used to simplify the network architecture. For this reason network gets to be more flexible. Single fiber can be used to given the signals to various BSs. Each wave length is meant for various BS. To create network architecture simpler subcarrier multiplexing (SCM) is integrated with WDM. To make use of air interface correctly sectorization of cells through antennas is required. Single side band modulation plan can be used to lower the chromatic dispersion. Wave length allocation is completed based on the users needs.

Architecture Description

Connectivity between CS and BS is by fiber optic. Each BS is associated with fiber network via two fibers. One fiber can be used for uplink transmission along with other fiber can be used for downlink transmission. Fiber access network is employing WDM technology. Antennas using by BSs are sectored antennas. Because of WDM, our network becomes simple. Reflective Semiconductor Optical Amplifiers (RSOA) products are used due to their cheapness. It eliminates using costly devices.

fig 8. Overall RoFnet Architecture

The bottom station schematic is proven within the figure.

Fig9. Schematic of Base Station


The performance of RoF systems might be seriously impaired by fiber chromatic dispersion. [13] The optical single side band (OSSB) modulation can be used for this function.


RoF has additionally many applications in numerous areas.

Use of dead zones

Because of RoF you’ll be able to provide wireless services to individuals places that wireless backhaul link isn’t feasible. They are dead zones like tunnels, secluded places like jungles, areas behind structures or mountainous regions.

Mobile systems are among the applying RoF. Mobile subscribers are growing progressively using their high traffic demands. RoF has capacity to satisfy their demands affordably.

Fixed systems are individuals systems where user lacks mobility. RoF technologies have its applications in fixed systems. For the reason that of their capacity to supply broadband services not only to mobile users but additionally fixed network users. It supports high data rates of approximately 155Mbps per user.

Because of lightweight, fiber optics is becoming very attractive in satellite communications. RoF is dependant on centralized system which centralization works well for satellite communication where high frequency equipment could be centralized to lessen the expense.


RoF has turned into a key solution for broadband communication. Different ways are utilized to transport signals in RoF. To suggest its uses in numerous areas, different architectures happen to be suggested. SCM and WDM are utilized in RoF systems. By integrating WDM and SCM in RoF systems, quantity of users could be further elevated. That’s the reason it’s large applications in mobile, fixed and satellite communications.

Request Removal

If you’re the initial author of the essay with no longer want the essay printed around the United kingdom Essays website then please click the link below to request removal:

More from United kingdom Essays

Share this:
custom writing low cost
Order custom writing