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AVIAT AVIA T NET WORKS
FROM BASIC CELL SITE TO INTEGRATED SERVICE DELIVERY HUB
THE TRANSFORMATION OF THE ”LAYER 2” CONNECTED MOBILE CELL SITE
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Mobile cell sites are transitioning transitioning from simple base stations for voice and low-speed mobile data access to multi-functional multi-functional hubs for delivery of new services, multimedia-rich content and broadband data access. Existing mobile backhaul solutions make this transition difficult as more capacity and smarter devices complicate cell site configurations, increase cost and add management overhead. This paper presents a new integrated inte grated cell site architecture that promises to transform the cell site and restructure restruc ture the mobile backhaul cost equation— making the new service-delivery cell-site vision possible with fewer boxes and simplifying simplify ing tomorrow’s tomorrow’s mobile network.
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THE EXP E XPANDING ANDING ROLE OF THE MOBILE MOB ILE NETWORK NET WORK In the past, mobile networks were built to deliver voice services with data connectivity services as a secondary consideration. Today’s mobile networks are being relied on to support mission-criti mission-critical cal business objectives, which are far beyond the realm of basic mobile connectivity. New enterprise, government, videoconferencing, social media and mobile commerce services place growing demands on the network in terms of capacity, security and reliability. The mobile network infrastructure must be flexible enough to deliver a growing number of new services with ease and cost effectively.
Moreover, capacity Moreover, c apacity demands are driving new levels of network densification by leveraging small cell, Wi-Fi and Cloudbased RAN RA N (C-RAN) architectures. While the densification “end game” is hard to pin down, what is certain cer tain is the mobile network needs to be flexible to support a considerable amount of future uncertainty. To meet subscriber coverage goals, and considering consumer demand for more mobile applications and that the mobile network operators (MNOs) desire to enrich their service offerings, lower costs and grow average revenue per user (ARPU), the cell site is undergoing a transformation.
Increase ARPU via New Services
Impr Im prov ove e Su Subs bscr crib iber er Re Rete tent ntio ion n
Red educ uce e Ne Netw twor ork k CA CAPEX PEX and OPEX
Enterprise
Performance
Fewer Boxes
VPN, enterprise access, enterprise application acceleration
Improved network performance for voice, video and data services (including (includi ng network networ k densification)
Common IP network infrastructure
Consumers
Services
Less Complexity
Optimized social media access, M-commerce, Videoconferencing, Security Services
Specialized services increase stickiness
Simplified operations and network management
Other
Security
Future Proof
Public Safety, Government
Security and privacy policies
Architecture to minimize ongoing investments
Table 1: Mobile Operator Objectives
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THE MOBILE CELL SITE AS A SERVICE DELIVERY HUB
CELL SITE ROUTERS: ROUT ERS: THE REQUIRED INGREDIENT FOR CELL SITE TRANSFORMATION
Operators need to enrich their offerings to attract and retain high value customers to offset the low ARPU for traditional consumer-level mobile users. To support new business initiatives, fast and flexible delivery of new services is necessar y. This fact, combined with the pending network densification, means the cell site must evolve.
Traditional Carrier Ethernet (i.e., Layer 2) advoc ates believe cell sites should be maintained at a Layer 2 (L2) implementation, implemen tation, citing a lower cost and simpler network infrastructure compared to Layer 3. IP (i.e., Layer 3) intelligence intelligenc e at the cell site gives the operator flexibilit y to support new scalable, high-quality services serv ices and the pending mobile network densification. Based on this, below are some reasons why routers at the cell site are poised to become the norm in future mobile network architectures.
The mobile cell site needs to evolve from simply housing a base station to supporting a network architecture that accelerates the delivery of new services to achieve business goals—the service ser vice delivery hub. IP is the only proven, scalable, futureproof technology upon which w hich to meet these goals completely completely..
NEW SERVICE DELIVERY
Many enterprise, government, videoconferencing and banking services can be delivered much more efficiently and at lower cost over a routed network. net work. For example, Layer 3 VPN services often provide the most flexible solution for enterprise access and connectivity services—especially as service requirements expand. Many of these transport connections will terminate ter minate directly at the cell site. On-site routed infrastructure can provide optimum flexibility to support the full range of access services including IP VPN, L2 VPN, VPLS, MPLS VPN, etc. to ensure overall business objectives are met.
COMPLEX, NON-INTEGRATED
Transport (MW, OTN, etc)
Cell Site Router
Enterprise Services
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2G, 3G, 4G Services
Small Cell
Streaming, Video Conf., Social Media, M-commerce
LOWER COST
SECURITY
Layer 2 is often believed to be a lower CAPEX solution, but many times requires higher OPEX—especially as the network changes and grows and new services are of fered. Traditionally,, IP routers have commanded a higher price Traditionally pr ice tag due to the higher cost of the silicon chips they required. However, newer technologies coupled with a highly software softw are driven paradigm and the fact that cell sites do not need the same level of performance perfor mance found in traditional routers makes routing at the cell site cost effective.
Layer 3 intelligence at the cell site provides many security benefits. Because mobile security requirements continue continue to evolve, routers offer optimum flexibility (e.g., having the ability to initiate and terminate IPSec) and the abilit y to support ever-changing ever- changing security requirements. Ultimately, ensuring both control and bearer channels are carried in the most secure fashion possible.
NETWORK DENSIFICATION
IP routers at the cell site enable the network to better deal with capacity challenges. By having the intelligence intelligence to route around issues, routed r outed intelligence at the cell site can have a great effect on capacity. c apacity. When compared to flat Layer 2 networks, routers scale to vast numbers of nodes, thus, giving flexibility to grow the network seamlessly with a lower total cost of ownership.
The network edge is constantly evolving, resulting in today’s edge sites becoming aggregation nodes—where IP and Multiprotocol Label Switching (MPLS) are now commonplace. In addition, the network needs to be flexible to support the evolving network net work topology. Layer 3 intelligence makes it easier to change the network topology (e.g., add a site, mesh to rings). With a mesh of L2 connections, for example, operational complexities can re sult in huge costs and slow the pace of the networ k evolution— meaning delays in new service offerings of ferings or improving network performance. MULTI�SERVICE CONNECTIVITY
New services, and network networ k densification means the emeremergence of a multitude of devices at the cell site. Many of these devices are multi-service interf aces and many can even include legacy interfaces such as TDM, ATM or even FR/ X25. Routers are the only proven solution to to cost effectively converge multi-services interfaces onto a single low cost IP transport. Also, Al so, with the migration to LTE/ LTE/ HSPA+, native IP is the default transport transpor t technology.
HIGHER CAPACITY AND NETWORK SCALABILITY
X2 INTERFACE
The interface between eNodeBs in LTE architecture, X2 creates significant challenges for network architects. Carrying Carry ing up to 10 percent of an eNodeB’s eNodeB’s total traffic, the X2 has extremely low latency requirements and is a key connection to support mobile handoff. When eNodeBs are on different subnets, a router is required to pro vide X2 connectivity and avoid storms of broadcast traffic. A more scalable X2 infrastructure is achieved by supporting router functionality at the cell site. Cell site routers are an essential investment to support the expanding role of the mobile network.
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MICROWAVE BECOMING MORE COMPLEX, LESS INTEGRATED Despite all the benefits, the addition of the router adds a completely new level of complexity complexity to the transport tr ansport network of microwave connected cell sites. Routers can be deployed alongside a microIF Connected wave indoor unit in a ODU split-mount microwave scenario or connected directly to an ODU (outdoor unit) in an MICROWAVE INDOOR UNIT DUMB all-outdoor Ethernet scenario. In either case, ROUTER routers are not well integrated into the microwave transport network, which can cause a host of challenges for operators. Five key challenges are listed below: MANAGEMENT COMPLEXITY
Separate devices, with different dif ferent management management interfaces, create a multitude of operational challenges. End-to-end configuration, provisioning, fault and performance per formance management can be difficult especially e specially in IP MPLS configuration. LACK OF DYNAMIC BANDWIDTH AWARENESS
The router does not have awareness into the microwave radio’s link bandwidth. Without this knowledge, traf fic engineering and L2/L3 routing become very dif ficult. In addition, Adaptive Coding and Modulation (ACM), which results in dynamic reduction of link bandwidth, makes matters worse. Network Networ k performance is drastically affected in the above scenarios where routers are “flying blind” and not aware of the actual bandwidth available in the network. POOR FAILURE DETECTION AND RECOVERY
In the above scenarios, the router generally does not know what the microwave radio is doing in r elation to failure recovery. Separate boxes require complex signaling/interworking that is not well coordinated. Also, there is a lack of integrated failure recovery across all layers including the IP/MPLS layer.
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NON�INTEGRATED RF
The above options all involve Ethernet connections f rom the router to the microwave device, either baseband unit or ODU. This is a departure from traditional microwave architectures—which have worked well for years and represent 95 percent of all All Outdoor Ethernet Radio microwave deployments today, where a microwave OR DUMBER baseband unit is connected to the RF unit with an intermediate frequency connecROUTER tion over the COAX cable interface. With the router + Ethernet RF unit options, the modem is in the ODU on the tower, which requires a tower climb for any modem upgrades. The multitude of protection options (e.g., 1+1, N+0, SD, FD) gets extremely complex, and many configurations are not supported. The T he cabling is also a challenge. Existing COAX cable infrastr ucture cannot be reused, and many new cables are often required (RJ45 Ethernet has limited distances so optical cables need to be run in addition). Power over Ethernet (PoE) injectors are also generally required often necessitating purchase, deployment and ongoing maintenance maintenance of a separ ate box. In summary, the lack of RF integration on these router + Ethernet radio configurations spells trouble for mobile network operator (MNO) operations teams. LACK OF INTEGRATED SYNCHRONIZATION, SECURITY AND QOS.
Router + Ethernet ODU solutions lack an integrated security policy across all layers layer s and boxes. They also lack automatic alignment alignment of QoS policy across acros s all layers leading to a complex operations effort to manage and maintain end-to-end end-to-end QoS policy. Also, because of the lack of integration, clock source change on router re sults in a network wide microwave outage.
INTRODUCING AVIAT NETWORKS’ CTR8500 MICROWAVE ROUTER CTR8500 MICROWAVE ROUTER
Enterprise Services
2G, 3G, 4G Services
CTR8500 is the industry’s first purpose-built purpose -built microwave router.. A microwave router is a new concept that merges router functionality of a microwave indoor unit and cell site router into a single integrated solution. In other words, CTR8500 is a full-featured router, purpose-built for microwave. micro wave. Unlike current generation microwave communications, communica tions, which requires separate separ ate non-integrated routers, CTR8500 CTR85 00 is an integrated solution reducing the number of devices, saving money. CTR8500’s “3-Level Integration” provides seamless interworking of microwave, routing and management domains, creating better performing microwave networks, simplifying your life. Best of all, CTR8500 CTR850 0 is also a powerful Layer 2 microwave
Small Cell
Streaming, Video Conf., Social Media, M-commer M-commerce ce
solution that can be deployed today and is IP/MPLS-ready via simple software upgrade for optimum flexibility and investment protection, safeguarding your future. CTR8500 is the first solution that allows operators to simplify cell sites, enhance ability to deliver new ser vices and lower CAPEX/OPEX; saving money, simplifying lives, and safeguarding the future. To meet aggressive business objectives, the mobile network must evolve and today’s mobile cell sites must transform into multi-functional, flexible service delivery hubs built on 3-levels of intelligence. CTR850 0 is essential functionality to enable this transformation.
3LEVEL INTEGRATION
INHERENT MICROWAVE
INTUITIVE MANAGEMENT
INTERACTIVE ROUTING
Microwave behaves as a traditional split-mount system with baseband and RF units being one tightly connected platform with fewer power, cabling and modem upgrade complicatio complications. ns.
One logically managed entity with a single interface. interface. Automatic alignment of security, synchronization, and QoS policy for trouble free network operations.
A full-featured router, purpose built for microwave, incorporating latest in routing standards and features and integrated completely with lower layers.
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