Yes, LTE is being heralded around the world as the next phase of cellular mobile communications. But important business, technology, marketing and operations alignment must first be considered by mobile operators as part of their LTE planning. LTE brings a major transition of the mobile network to an all-IP network. Here are some key things to consider, based on conversations with operators. The Business Plan - Question number one that operators bring up is “What is the right time for me to launch LTE?” And then followed by “Can I make money on this?”, “Is my market ready to pay for faster speeds and more bandwidth?" and “Can I launch better applications that my customer base can pay?” Some markets are more mature than others so this should drive how quickly an operator offers LTE. Another aspect to consider is the competition and when they will be moving to LTE. Failing to meet the competitive challenge could lead to loss of market share. The capital and operational costs for the new radio and backhaul infrastructure should also be factored in to a LTE business plan to gauge the time to return on the investment. New Business Models - Associated with LTE discussions are new business models for operators. The significant CapEx and OpEx involved in   running a LTE network is requiring operators to think in different ways. Network sharing, partnering, and colocated cell sites are becoming important in many parts of the world. Operators are tossing around ideas to leverage backhaul from a common provider. Sharing facilities and related infrastructure are being explored. Managed content with revenue sharing models is becoming the norm. Backhaul - How LTE backhaul is deployed could make or break the payback on a LTE deployment. Backhaul is the highest OpEx cost for operators. Mostly, it has been agreed that Ethernet is the way to go for backhaul. But Ethernet is not yet available to every cell site. At lower bandwidth speeds (8-10 Mbps), T1s or E1s still make sense. But T1s and E1s cease to be economically feasible once the operator has 7 or 8 of them. That’s when it’s time to go to Ethernet, but planning should begin before this threshold is reached.   Still, some of the big operators are using T1s in the U.S. and losing money in the interim. The major reason they haven’t transitioned to Ethernet is lack of familiarity with IP and tools among their engineers. It’s been hard for them to break away from TDM. But that transition in technology and skills is underway. As for smaller operators, a big question is “Should I build or lease LTE backhaul?” While it is less expensive to lease at lower traffic volumes, operators who choose to do so will lose the ability to customize topologies and optimize for X2 handovers and latency-sensitive applications. The leasing option will work out for many operators with proper QoS planning. Evolved Packet Core (EPC) - The Mobility Management Entity (MME), Serving Gateway (SGW) and Packet Data Network Gateway (PDN GW) that are the building blocks for the EPC can be deployed in different degrees of distribution. Choosing the most optimum option is dependent upon latency requirements, mobility events, application requirements, traffic patterns, number of subs and cost of backhaul vs. offloading locally to the Internet. The deployment options include: Centralized model, where the three EPC elements are located in a few central sites (usually less than 5) Distributed model, where the EPC elements are located in a relatively large number of sites (usually more than 25) Regionalized model, where the EPC elements are located in a limited number of regional sites (usually more than 5 but less than 25) Another important aspect is choosing the combination of gateways and MME at a particular location. Based on the above factors, it is almost a given that SGW and PDN-GW will be co-located. MME in the initial stages can be more centralized but eventually will be equally distributed as SGW and PDN-GW because of the mobility event considerations for VoIP and real time applications. Finally, what are the policy control and charging mechanisms most appropriate for LTE? How much deep packet inspection and billing are important in LTE? Deep packet inspection with policy will grow in significance – albeit with simplistic enforcement and policies tied to consumer offerings. Operations - LTE is an all-IP network environment, so the skills, processes, tools, and templates will be different from the existing Telco environment. The mobile operators need to prepare their operations team for capacity and performance planning and new troubleshooting methods. Another important operations aspect is “How do I transition and integrate LTE offerings to my existing services and users without adversely impacting them?” IP Planning - Most people expect that IPv6 will go hand in hand with LTE. But questions include “What changes will have to be made to enable IPv6?” and “How operationally intensive will the transition from IPv4 to IPv6 be?” Also, “When will be devices be ready for my market that support IPv6?” There are three choices for IPv6 deployment: Launch with IPv4, launch with handsets using IPv6 and maintain IPv4 for infrastructure, or launch using IPv6 end to end. Each option has implications on the readiness of the network for IPv6, operations readiness and requirements for 6-4 NAT. Security - The added bandwidth in LTE makes it more important for mobile operators to move to true service provider-class security tools instead of relying primarily on firewalls. The key difference is automatic instead of manual features in tools like Unicast Reverse Path Forwarding (uRPF) and Remote Triggered Backhauling (RTBH). The key is to safeguard your infrastructure from external traffic (e.g., from users, the Internet, and partners) and allowing other interactions beyond the gateway. Datacenter - How would the datacenters evolve as more services, content and servers are put into the network. This increases to cost of operations, power, maintenance and further engineering. How can virtualization ease these costs? How can the datacenters consolidate staorage and reduce cabling costs? How can the next-gen datacenters leverage clouds? How to architect a datacenter that provides consistency, scalability and has limited layer-2? MPLS Core - Most mobile operator concerns on MPLS Core is around scalability. As we move towards LTE, the question of being able to provide cheap transport vs. quick internet pipe will drive the degree of distribution of EPC core. IP Multimedia System (IMS) Strategy - This is not an immediate concern for operators but it is something that they are curious about. IMS is the direction for most operators when they consider offering Voice over LTE (VoLTE). Right now, it is expensive to implement and is operationally challenging. So in the meantime, “How does the operator work towards an IMS-Lite deployment?” and “What is the minimal VoLTE service that you can get away with?” Radio and RF Strategy - It is important to ask “How do I best optimize the CapEx investment for the new LTE radios?” and “What and how much spectrum can be used?” If the spectrum needs to be re-farmed, then “What is the implementation plan?” and “Should LTE be deployed throughout the entire market or just the hot spots?” Also, “Is consumer and enterprise Femtocell going to be part of my radio strategy?” and “What is my 2G/3G fallback plan for non-coverage areas?” Operators continue to think of Wi-Fi as a short-term offload strategy, but “Can it be a long-term plan?” LTE brings Self Organizing Networks (SONs) which will be evaluated in the next phase of radio expansion. Devices - Items that have dependencies on devices are – IPv6 support; multiple radio fallback technologies, spectrum, global and local roaming; primary and secondary PDP concept to ensure differing QoS for different applications. Other regular considerations are size and power consumption. And the price points need to appeal to operators and their consumers. LTE is an all-IP network that requires a high degree of readiness for deployment. Readiness on eight different metrics is discussed here briefly (I will expand on this in one of the future blogs). It is also important to highlight the organizational impact of a flat network in LTE, discussed here and in a second blog . So as you can see, there is a lot to think about when planning for LTE. What’s on your mind? ... View more

Mobile operators want an assessment of how they can evolve their environment to be LTE ready. Going from 2 Mbps peak downlink rates with basic 3G to 50-100 Mbps with LTE—among numerous other great new all-IP capabilities and their impact—has gotten every operator’s attention. But what does the move to LTE entail? And how much will it cost? And how can the evolution to LTE be as seamless and painless as possible? To get ready for LTE, mobile operators must align the three dimensions of business, technology, and operations. This involves asking and answering a variety of questions and collecting metrics and other information about the following: Business Alignment includes a clear articulation of what business drivers make it necessary to move to LTE. What is the cost and benefits equation? Is the market clamoring for LTE or can the operator wait? What are the new business models for the cost effective running of the enhanced network? What is the impact on the vendor ecosystem? What are the new business initiatives that need to be driven? What is the impact to the internal organization? This was discussed in two recent blog posts; Organizational Impact of a Flat Network and LTE Brings the Importance of Organization Collaboration). Are particular applications or partnerships behind the need for LTE features? How can services that rely on LTE be marketed to appeal to customers and increase ARPU? What are customer requirements for those services? What are the operator's medium- and long-term objectives and timelines with LTE and what specific new services will be introduced? What are the price points for the devices? Should LTE be introduced first only in hot spots instead of throughout a mobile operator's entire market? If an internal or external consultant is conducting the assessment, discussions with key executives who are responsible for strategy and marketing will be crucial. Technology Alignment begins with clearly understanding the current network state and then determining what technologies and platforms must be added or can be reused for offering LTE services. Architectural layers and service elements include the radio, backhaul, aggregation layer, network core with the gateways, data center, and services and applications. How do these areas stack up today in terms of their IP evolution with respect to the IP Index and Key LTE Metrics (discussion here)? What areas need improvement? How does the network compare with comparable networks based on industry best practices? The result of this aspect of the readiness assessment is an analysis and findings and then an LTE architecture and design blueprint. Key LTE performance metrics should be used when proposing an architecture and design, IP implementation plan, and upgraded approaches to scalability, resiliency, security, QoS, latency, mobility of applications, and management. Impact relating to call flows, roaming, and service offerings must be evaluated. Decisions related to the degree of distribution of gateways, IPv6, policy, deep packet inspection, and billing are all part of the technology alignment. Operations Alignment for LTE should encompass the tools, processes, and skills necessary to support the IP and Ethernet environment required for higher speeds, capacity, and features of LTE. Another important aspect to consider is that the existing services must not be impacted during this transition. The existing traffic (especially data traffic) may need to be migrated to the new infrastructure and that may be more cost effective, an example being backhaul. What legal and regulatory requirements (e.g., Legal Interception, 911 routing, etc.) must be considered? Are there different features that must be included in LTE support models that differ from those used currently? Leading industry analysts believe that most mobile operators will be moving to LTE within the next three years, so it isn’t too early to begin asking these and other questions. LTE is likely to be a lot more than just a technology enhancement. Given the rapid pace of social networking, business collaboration, and other user-driven behavior that is extending beyond traditional network borders, LTE will probably quickly spawn new applications and new opportunities. It’s hard to anticipate what pressures these will bring to mobile networks, but now is the time to carefully plan the move to LTE and to ask the questions, gather the metrics, and devise solutions based on what we know now. ... View more

In an earlier blog entry, we discussed "Organizational Impact of Flat Network". Another key aspect from an organization perspective is Collaboration across the company that is critical for an-All IP network. Lets contrast with what exists today: Today, mobile networks are hierarchical in terms of location and architecture - cellsites, MTSO that houses BSCs and RNCs, Regional Datacenters that have SGSN and MSCs, National Datacenters that may have GGSN (This is an example of more centralized architecture, there could be more distribution, not relevant to the point). Many of these components are traditionally not IP based and have all different variations of transport between them (TDM, Frame Relay, ATM and more recently IP). So if you really look, there are "silos" of network components. LTE network is an All-IP network, all components and transport between those components is IP. Why is Collaboration so important in an all-IP LTE network? Some examples will help here to illustrate the point: Take an example of routing. Since the entire network is an all-IP, if you mess up routing at one cell-site (example, add a default route and propogate), it has a potential of bringing down the entire network. [I had to put this example because it is so easy to understand, even though I hope networks will not be designed this way, take this example for the concept] Lets discuss IPv6. When a mobile operator has to transition to IPv6, can you point me an area of the network that will not be touched upon? Security is another great example. Mark in the blog referred above, mentions a great example of collaboration between Core, Transport and Radio teams to bring security together for S1/X2 interface. Capacity Management: Already operators are seeing where if they plan capacity in silos, they continue to fight fires. Some more thoughts here on capacity management. What does it take for an operator to get to Collaboration? Its important for executives to realize and drive this. For a couple of operations that I got a chance to emphasize this point, we worked on "Collaboration Lifecycle" approach for their teams to redefine the interactions among their teams. We also helped create some virtual teams - example a VT for IP Planning, another one for Security etc. And then executive sponsors governing these VTs. Your thoughts? ... View more

Everyone is excited about the Flat Network in Long Term Evolution (LTE) and its advantages e.g. reduced latency, better operations efficiencies, lower costs etc. What about Organizational Impact for operators? Its not an easy topic to discuss, and still is so much critical. And it has impact. Based on my interactions with operators that have a 3G network and moving towards 4G, there are many organizational impacts of a flat network architecture. Following are few major themes that I have seen: Service Providers have teams built around platforms, i.e. a team to design, manage and maintain a set of platforms. If  the network becomes flat i.e. less architecture elements, then there would be less teams managing the lesser number of platforms. In the short term - 3G network has to be managed, so its in the long run that the organizational decisions for 4G made today will have impact. Teams which already have IP skillsets and especially if those teams have proven well in 3G, these teams are pursuing aggressively in LTE. An example is MPLS Core team is asked to provide inputs on IP based Backhaul. Voice have interesting dynamics. Many of the IMS platforms in existing operators are not managed by Voice teams, rather either by IP team or application team. With Voice being called out as similar to any real-time application in LTE,  the dynamics becomes even further complicated. There are voice solutions of utilizing existing voice assets in LTE, which will be depoyed by many operators in earlier stages - pushing this problem out for now. Even more complicated are situations where the same operator had a wireline and a wireless arm. And in many cases, the wireline and wireless arms are integrating closely as wireless is becoming more IP/Ethernet centric andcarrying huge amount of traffic. And remember no two operators' organizations are alike. Its important to understand what got them there in the first place to determine how to evolve it. In some cases, I have suggested to our operator executives that they need to attack this problem sooner than later. There are steps that they can take immediately during planning: Define an organizational structure for LTE (how would it look like in long run, say 5 years - this is one of thr toughest things that executives like to avoid!) Define a path from the current structure to move towards the future. This is somewhat tied to LTE rollout plans. Communicate down to senior management, ensure to get their buy-in. Ensure that all the teams are trained in IP. Some of these steps will ensure that the operators can really reap the benefits of cost in a flat network architecture, align their teams and avoid confusion. I would really like to hear from you if you had been in similar situations. What were some of the considerations for impact to organizations as they move to LTE.  Which considerations were thought through and which ones were not. What was the direct or indirect impact of those. ... View more

LTE Gateways - Serving Gateway (SGW) and Packet Data Network Gateway (PDN-GW) are used for LTE bearer path whereas Mobility Management Entity (MME) is used for siganling. Lets look at hogh level functions for both the LTE gateways: Serving GW: provides mobility anchor for inter eNodeB handover and paging trigger for downlink traffic awaits user. SGW is also used for 3GPP Inter-RAT traffic with S4 connectivity to SGSN. For PMIP based version, it would provide bearer session management and control. PDN GW: provides connectivity from user to services. It provides network-wide mobility anchor, including for non-3GPP technologies. It provides bearer session management and control. With PMIP version almost on hold after Verizon made a decision to use GTP, Serving Gateway's role as a separate entity provides very little function that PDN-GW does not perform, essentially data path mobility management events (paging trigger and eNodeB handovers). Does this justify a separate entity in the data path with high throughput handling capabilites? An additional cost for operators? An additional question - does it need to colocate SGW? Should SGW and PDN-GW be hierarchical in nature? There are discussions on local offload at different hierarchical levels. With a merged gateway, the local offload feature is same as SGi, reducing one more complexity. Reducing latency on real-time applications including VoIP will be an easier discussion. Should 3GPP standard look at combining the two gateways? In my view, it should. What are your thoughts? ... View more