**5. Conclusions and chapter summery**

Mobile and wireless networks generated traffic rates are growing very fast and are expected to double each year. The expectation is for delivering at least 1 Gbps multi-services traffic to each end-user in the near future for personal and multimedia communication services. Therefore, deploying super-broadband networks will be essential for service providers and operators. In this chapter, the convergence of wireless and optical communication technology for deploying future super broadband networks has been discussed.

Fiber optic transmission is rapidly becoming the dominant infrastructure medium for the transportation of fixed and mobile video on the internet. By replacing electronic switching with ultra fast photonic switching fiber optic transmission is expected to meet the need for super-broadband capacity. Radio-over-Fiber is a potential solution for deploying wireless access to broadband and super-broadband seamlessly. It can provide dynamic allocation of resources and can be realised with simple and small BSs with centralized operations. The requirement for more bandwidth allocation places a heavy burden on the current operating radio frequency (RF) spectrum and causes spectral congestion at lower microwave frequencies. Millimeter wave (mm-Wave) communication systems offer a unique way to resolve the bandwidth problems. When heterogeneous access networks converge to a highly integrated network via a common optical feeder network, network operators can reap the benefits of lowering the operating cost of access networks and meeting the capital costs of future upgrades easily. In addition, the converged access network will facilitate greater sharing of common network infrastructure between multiple network operators. Radio signals transportation over optical fiber (RoF) links will be a possible technology for simplifying the architecture of remote base stations (BSs). By relocating key functions of a conventional BS to a central location, BSs could be simplified into remote antenna units that could be inter-connected with a central office (CO) via high performance optical fiber feeder network. Wireless networks typically show considerable dynamics in traffic load of the

Subsequent to the wavelength conversion, the digital photonic signals are multiplexed in the wavelength domain by using a WDM and transmitted over a fiber. At the BS, the received signal is demultiplexed by wavelength division demultiplexer (WDD) and fed to the photonic digital-to-analog converter (PDAC). The PDAC subsystem, receives digital optical signals on different wavelengths, and converts them back to the equivalent analog signal at wavelength λ by using a passive PDAC and all-optical wavelength conversion. In the following of this stage, by using a photo diode (PD), the RF signal is recovered and after

According to results provided (Abdollahi et al., 2011), it is demonstrated that ARoF is more dependent on fiber network impairments and length than DRoF. However, very low phase noise photonic sampling pulses and high speed signal conversion rates can be achieved in an all-photonic DRoF system compared with high-speed electronic circuits generated sampling pulses, signal conversion and processing. Consequently, an all-photonic DRoF system can support a digitized RF signal transmission system for providing superbroadband access to remote distributed wired and wireless access networks. It follows that, compared to the present digital optical communication infrastructures the number of CS would decrease with the introduction of all-photonic DRoF systems and as a result the

some RF signal processing it is passed to a multi-band distributed antenna system.

service providers and network operators cost overheads per bit would be reduced.

technology for deploying future super broadband networks has been discussed.

Mobile and wireless networks generated traffic rates are growing very fast and are expected to double each year. The expectation is for delivering at least 1 Gbps multi-services traffic to each end-user in the near future for personal and multimedia communication services. Therefore, deploying super-broadband networks will be essential for service providers and operators. In this chapter, the convergence of wireless and optical communication

Fiber optic transmission is rapidly becoming the dominant infrastructure medium for the transportation of fixed and mobile video on the internet. By replacing electronic switching with ultra fast photonic switching fiber optic transmission is expected to meet the need for super-broadband capacity. Radio-over-Fiber is a potential solution for deploying wireless access to broadband and super-broadband seamlessly. It can provide dynamic allocation of resources and can be realised with simple and small BSs with centralized operations. The requirement for more bandwidth allocation places a heavy burden on the current operating radio frequency (RF) spectrum and causes spectral congestion at lower microwave frequencies. Millimeter wave (mm-Wave) communication systems offer a unique way to resolve the bandwidth problems. When heterogeneous access networks converge to a highly integrated network via a common optical feeder network, network operators can reap the benefits of lowering the operating cost of access networks and meeting the capital costs of future upgrades easily. In addition, the converged access network will facilitate greater sharing of common network infrastructure between multiple network operators. Radio signals transportation over optical fiber (RoF) links will be a possible technology for simplifying the architecture of remote base stations (BSs). By relocating key functions of a conventional BS to a central location, BSs could be simplified into remote antenna units that could be inter-connected with a central office (CO) via high performance optical fiber feeder network. Wireless networks typically show considerable dynamics in traffic load of the

**5. Conclusions and chapter summery** 

radio access points (RAPs), due to fluctuations in the number mobile and wireless service users using them and the services they demand.

On the other hand, using the traditional RAPs approach requires equipping all of the wireless nodes for the highest capacity demanded which results in the inefficient use of recourses. The design ofdynamic reconfigurable micro/pico or femo wireless cells increases network complexity but also greatly increases network efficiency. Within the optical access network layer WDM PONs allow an extra level of reconfiguration as wavelengths can be assigned to channels as part of static or dynamic routing. Therefore, integrating dynamic wavelength routing with RoF technology facilitates future flexible, low cost and reconfigurable super-broadband wired and wireless access network.

DRoF links are more independent of fiber network impairments and length than ARoF links. By using very low phase noise photonic sampling pulses and high speed signal conversion rates in place of high-speed electronic circuits generated sampling pulses, signal conversion and processing in an all-photonic DRoF system, digitized RF signal transmission for delivering future super-broadband remote distributed wired and wireless access networks traffic can be realised. Consequently, compared to the present digital optical communication infrastructure the number of CS will decrease in an all-photonic DRoF infrastructure and as a result, service providers and operators cost overhead per bit will be significantly reduced.
