Fiber Optic Networks for Distributed, Heterogeneous

1. Fiber Optic Networks for Distributed, Heterogeneous Radio Architectures and Service Provisioning: The case of the FUTON programme G. Heliotis, I. Chochliouros and G. Agapiou Hellenic Telecommunications Organization (OTE) S.A. Dept. Of Network Strategy and Architecture

2. Outline • Quick facts about the project • Introduction & motivation • Basic architecture • Objectives • Benefits • Summary - conclusions

3. FUTON in a Nutshell… • FUTONis a collaborative EU funded project: • 30 months, 16 partners, started: 03/08 • Leader: Nokia Siemens Networks • Aim: Develop a transparent fiber infrastructure that will act as an enabler of new wireless architectures • What will this infrastructure offer? • Possibility to perform joint processing at a central location • Enhanced cross-layer algorithms • Enhanced cross-system algorithms • FUTON will cover: • Concept definition and network design • Implementation and validation of basic blocks • Study of business impact and deployment + VIVO (Brazil) + NICT (Japan) • FUTON consortium balanced between academic/ research institutes, manufacturers and operators

4. Introduction Europe’s future communications networks promise to usher in a new world of business and lifestyle-enabling capabilities  Some key aspects that will characterize these networks are: • Convergence/interoperability of heterogeneous mobile and fixed broadband network technologies, enabling ubiquitous access to broadband mobile services. • Optimised traffic routing and processing between core and edge networks, that will enable ultra high speed end-to-end connectivity • High scalability, allowing a great increase in the number of connected devices and enabling the emergence of novel application opportunities • Flexible, optimised control and management procedures that will enable seamless service composition and operation across multiple telecommunication operators and business domains • Support of a wide diversity of complex service attributes and requirements, with intelligent distribution services across multiple access technologies

5. Service Trends and Requirements • Future services will predominantly be offered on an “on-demand” basis and will be highly demanding in terms of bandwidth. • Will, therefore, require high levels of capacity, configurability and resiliency from the underlying communications infrastructure. • Wireless or converged fixed/wireless networks should: • Offer high capacities to all potential user categories and support wide variety of either nomadic and being “on-the-move” interoperable devices and services, a variety of content formats and a multiplicity of delivery modes • Guarantee robustness, resilience, trust and security in service platforms that are much larger in complexity and scale than currently. • As such, European telecommunications operators should aim to develop new network infrastructures that will: - overcome the long-term limitations of current implementations - will be driven by the need for generalised mobility, high bandwidth, scalability, security and support of a multiplicity of multimedia services

6. Scope of the FUTON programme • ●Currently, two major trends in wireless communications are: • - development of a new broadband component • -integration of the variety of heterogeneous wireless technologies • ● FUTON takes into account these two trends and aims to address the • growing demand for wireless services • ●FUTON aims to develop a system for wireless service provisioning • with: • - True Broadband access • - Increased system capacity

7. Conventional cellular architecture • Main elements of current architecture: • GSM Base Transceiver Stations (BTS) or UMTS Node Bs connect users to the • network and perform signal processing tasks • These are in turn connected to a Base Station Controller (BSC) through microwave • links or cable. • The BSC provides the “intelligence” behind the BTSs and controls a large number • of them. It handles radio channel allocations, controls handovers etc and acts as a • traffic concentrator towards the core network. * Space multiplexing by treating radio signal from other cells as unknown interference

8. BTS RAU BTS RAU BTS RAU  What would be an obvious solution to increase the system capacity? • Cellular planning → Reduce cell size • Do not treat signals from the different cells as unknown interference Reduced processing RSS Central Unit Joint Processing (detection coding, resource managing) RNC Service data Radio signals transported transparently  Allows soft combination / processing at the Central Unit (CU)  Signals from different cells not treated as interference

9.  What about the link capacity? • Have mobile devices communicating simultaneously with several antennas (similar to MIMO concepts) • Conceptually, this allows the antennas to be treated as physically distributed antennas of one composite base station. High Co-operation is needed.  The key to achieve high cooperation is to have the radio signals transparently transmitted/received to/from a central unit where all the signal processing is performed

10. FUTON’s proposed solution • The network capacity (users/Km2) problem and the link capacity problem point to the same solution: • Perform a joint processing of spatially separated radio signals • Build an infrastructure that collects / distributes the radio signals from the different antennas • The technology to build that: optical fiber • Huge bandwidth • Low losses

11. Radio-over-fiber (RoF) again? • Generalized RoF network for application in cellular networks is a resurgent idea but up to now not has not taken place • RoF has always been thought of as a remoting or extension component • Optical components still expensive to provide a clear balance towards the use of generalized remote antenna units in 2-3G • Trends call for a joint processing of distributed radio signals  what is needed is much more than remoting ● Shift the vision of RoF as a remoting component to one of an enabling infrastructure for joint processing at a central location or distributed processing of the radio signals THIS IS THE OBJECTIVE OF FUTON

12. FUTON Architecture • FUTON: Hybrid optical/radio infrastructure with distributed RAU units and joint central processing FUTON architecture for various single serving areas connected to same central unit • Geographical area to be covered is divided in serving areas (or supercells), where multifrequency RAUs are deployed and are linked to a central unit through optical fiber connections that transport the radio signals transparently • Different systems can coexist and be connected to the same central unit

13. FUTON: Summary of Objectives • Technical level • Deployment/ business level • Evaluate the implications on the current wireless architecture models of the FUTON concept, determine cost models for upgradeability / replacement and provide roadmaps for evolution.

14. Main Benefits I on a technical level • FUTON’s architecture is inherently flexible and easily upgradeable, and provides a promising framework for the efficient integration for fixed and wireless technologies. • It can facilitate the design of efficient cross-system algorithms / protocols, and enhance interoperability between heterogeneous systems • It has the ability to achieve the very high bit rates sought for the broadband component of future wireless systems, and an increase in the overall system capacity • Overall, for network operators, it will provide a scheme with high reusability, easy upgradeability (in order to accommodate new services and cope with the increasing bandwidth demands), flexibility to provide ease of reconfiguration, and convergence

15. Main Benefits II on a business level • Provisioning of new broadband wireless services with several use-cases • Owner of the RoF can be third party → infrastructure need not be owned by a single operator that provides every service, but in fact, an operator can rent its usage to new wireless service providers • This will allow the operator to make extra revenues from its infrastructure, and facilitate easy entrance of new service providers, fostering innovation for the benefit of end-users • Overall, the programme is expected to reinforce European leadership in both fixed and wireless networks, developing stronger synergies between various telecommunications stakeholders and contributing to the emergence of new business models • New European industrial and service opportunities may arise as a consequence, especially in the rapidly advancing sector of mobile Internet access

16. Summary • FUTON is a very recent, ambitious European research programme, that aims to develop a new hybrid optical/radio infrastructure enabling high bit rates and enhanced system capacity • Proposes the development of a fiber-based infrastructure transparently connecting distributed antenna units to a central unit where joint data processing can be performed. • The FUTON approach departs significantly from conventional RoF (Fiber infrastructure not only for extension or remoting, but enabler for new wireless architectures and techniques) • Overall, FUTON aims at providing the long sought objective of broadband to the user but with mobility added

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18. FUTON: Consortium ►Leader:Nokia Siemens Networks(Portugal) ►Partners: - ΟΤΕ(Greece) - Instituto de Telecomunicações(Portugal) - Portugal Telecom(Portugal) - Motorola(France) - Alcatel-Thales(France) - University of Kent(UK) - Πανεπιστήμιο Πάτρας(Greece) - VIVO(Brazil) - Sigint(Cyprus) - Acorde(Spain) - Nippon Institute of ICT(Japan) - Jayteck(Poland) -Tech. University of Dresden(Germany) - VTT(Finland) - University of Aalborg(Denmark)

19. Transmitter Precoding Receiver Processing • MIMO • Separate streams at the antennas  multiplexing gain (R=min[Mt, Mr]) • But achieved only if the channel is rich scattered • But in mobile application, outdoor channel does not have too many major scatterers, resulting in strongly correlated channel  capacity scaling not achieved • Furthermore when more than one pair of MIMO users exist, interference to each other still exists, implying the requirement of joint processing of multiple pair of MIMO links • Solution: Build a MIMO system with far apart antennas

20. The components of the DWS I MT RAU OTI CU • MT: Mobile Terminal • RAU: Remote Antenna Unit • Unit that interfaces with the mobile terminal on one side and OTI on the other side • Gets / sends RF signals and transceives them to / from optical • OTI: Optical Transmission Infrastructure • Optical network connecting RAU ports to CU • CU: Central Unit • Physical location where the signals to / from the RAU’s covering a given area are processed

21. The Components of the DWS II • RAU_W (RAU Wireless) performs the transmitting / receiving functions that are independent from the OTI. • CSC_RAU (Conversion Separation Combination –RAU). Performs the signal conversions between the optical and electrical. • CSC_CU (Conversion Separation Combination –CU). • JPU (Joint Processing Unit). Unit where the joint processing of the RF signals for a set of RAU’s is performed. More Detailed view

22. Scenarios for Distributed Wireless Systems I • From an architecture point of view  identical to classical cellular network but with a distributed base station • Could allow some overlapping to facilitate handovers • Evolutionary path • The evolution of a legacy system (e.g. LTE), eventually with larger bandwidth and aiming at higher peak bit rates • The base stations are stripped versions of a full base station (only RF operation; s_BS) • Can be sectorized and/or have multiple antennas • The areas associated with each RAU are grouped to form a cell with distributed antennas • The signals from the RAU’s are transported transparently to / from the CU

23. Scenarios for Distributed Wireless Systems II UMTS legacy Evolution to DWS RNC  Physical location of CU Evolutionary scenario

24. Scenarios for Distributed Wireless Systems III • Advanced Scenario • Rationale • In future wireless networks one should have and accommodate • Ability to reconfigure on the fly to meet dynamic patterns • Need to provide simple ways to upgrade / reconfigure the network without need to redo a new planning • Implications in terms of the FUTON concept • RAU’s very simple • The “planning” should be a dynamic allocation of resources to be performed real-time at the CU • Area Covered by a Central Unit: Serving Area • The serving area can be quite large (e.g. equivalent to the area served by a RNC) • Joint processing area: set of RAU’s which are jointly processed • Overlapping may exist to facilitate handovers Page 24

25. The optical transmission infrastructure I Key aspects The issue - transport of analog radio waveforms or digitized radio over the fiber? • Key design aspects for the optical infrastrucuture • Should be easy to support new wireless systems • Should e easy to add new RAU’s, without need for a complete replanning Flexibility, reconfigurability Page 25

26. Digital Transport Specific design for each radio system Synchronization issues Offers noise immunity and protection against component impairments Very high bandwidth required Analog Transport The optical transmission infrastructure II • With combination of subcarrier multiplexing and WDM • high flexibility, transparency • Drawbacks • Dynamic range of optical links • Furthermore if signal are in digital format  can be transported like analog waveforms  provide easy integration of existing digital interfaces (CPRI, OBSAI) Page 26

27. The optical transmission infrastructure III • Resources of the optical infrastructure • Optical wavelengths • Electrical subcarriers ... Electrical subcarriers f3 f2 f1 l2 l3 l4 l5 l1 Optical wavelenghths Digitized radio signals Digital optical signal for the fixed network RF signal Reference RF signal Page 27

28. The optical transport infrastructure IV • Optical wavelength address the RAU’s • Electrical subcarriers, separate different systems / sectors / antennas at each RAU • Up and down converters  transport of signals in the range less than 10GHz where optical components with low cost and good linearity characteristics can be developed