LTE network infrastructure: Greenfield and brownfield network design

While paying close attention to user trends, operators migrating to LTE network infrastructure need to plan their greenfield and brownfield networks in harmony with each other, with existing 3G usage patterns as an aid for planning 4G wireless capacity, even though mobile backhaul solutions will be very different.

From the editor: While it's popular to talk about 4G wireless greenfield and brownfield network planning, operators have good reason to think of LTE network infrastructure decisions as "all-field," or working harmoniously in established and new network builds alike. In the final article in our Telecom Insights guide, Building 4G wireless networks: Exploring LTE architecture and services drivers, telecom expert Tom Nolle, president of CIMI Corp., looks at practical ways to make LTE network infrastructure work for existing and new wireless networks.

Don't miss any of the articles in this series on LTE:

LTE network infrastructure: Greenfield and brownfield network design
By Tom Nolle, President, CIMI Corp.

Deploying 4G wireless services is an acknowledgement of the transformational mission of mobile service in creating new opportunities. The term transformational is especially relevant because most 4G deployments will transform the business model and network infrastructure of current mobile operators.

Long term, operators believe that LTE network infrastructure planning will settle on a common model.


Tom Nolle
President, CIMI Corp.

 For current 3G operators that plan to evolve their services to a 4G Long-Term Evolution (LTE) wireless framework, LTE standards and specifications define a longer-term architectural model and provide guidance on how that evolution can be managed.

One challenge in making wireless evolution guidance practical and useful is that operators often see LTE as a greenfield (or new) network opportunity in one geography or application and as a brownfield network opportunity (a transition from existing infrastructure) in another. Even where operators have 3G infrastructure in place, their service goals may drive them to create a totally parallel and independent LTE network. Conversely, some new LTE operators may have to consider interoperability with 3G service providers for roaming and even interoperability between their own LTE and wireline networks. A harmonious approach to LTE is likely to be helpful to most operators at some point.

Radio access network (RAN) planning is a requirement for both greenfield and brownfield LTE network infrastructure deployments, but the information resources that drive it are different. Where 3G services are already deployed, the best strategy is to use 3G data usage patterns to identify the locations where LTE is likely to intercept the largest subscriber interest. When doing this, it is also critical to analyze shifts in the pattern through the day and also through the week. The extent to which demand patterns change may be an indication of the early need for such things as intelligent antenna systems to change cell coverage to match subscriber mobility.

Where there is no 3G data to rely on, it may be necessary to consider basic demographic information and consumer/worker behavior patterns. Most operators report that 3G data usage is highest where customers are at least somewhat idle -- in traffic, on public transportation or in hospitality locations. 3G data usage is also highest where the concentration of users includes a high percentage of youth -- those under age 25. This means that schools/universities and other natural congregation points for the young are likely to be the early 4G LTE opportunity areas.

Different LTE backhaul approaches for greenfield/brownfield networks

LTE mobile backhaul or connectivity is an area where greenfield and brownfield network approaches may be very different.

 Where 3G services are already in place, the backhaul capabilities for those services aren't likely to be directly upgradeable to LTE for capacity reasons, but rights of way and current infrastructure might be exploited. In an LTE greenfield network deployment, tower connectivity and mobile traffic backhaul to a service point will need to be created from scratch. This may also be the case where an operator is adding LTE to a 3G profile that includes many cell sites that are outside its own wireline network scope.

LTE greenfield network backhaul should consider service and revenue evolution carefully in order to avoid getting too far in front of the opportunity because the first cost is likely to be high and the economy of scale relatively low. With brownfield network upgrades to create LTE backhaul, it's probably best to look further into the future and "shoot ahead of the duck" to ensure that long-term costs are managed, because there's a higher likelihood that the economies of early deployment will be reasonable where exploiting some of the existing facilities is possible.

LTE service planning requires newfound flexibility to accommodate trends

In service planning, the 4G wireless brownfield network operator will not only have data from current services on which to base future service plans, it will have a customer base to specifically target with new LTE services. Greenfield network LTE providers may lack both of these assets. The service trends created by smartphones and application stores testify to the need for flexibility in creating and marketing new services in an LTE world, but there is a greater need for flexibility in the near term in greenfield applications. The lack of data on services and the lack of a customer base from which some degree of market control can be exercised make greenfield providers more vulnerable to market shifts. That is particularly true in a situation where the greenfield network LTE service is being introduced to compete with existing 3G offerings from competitors.

Operators believe that LTE deployment issues for brownfield network markets are more "contained," and the range of choices for a given technology or service can be constrained by knowledge of the market and the need to maximize current infrastructure and craft assets. Greenfield LTE network infrastructure, in contrast, provides greater flexibility in targeting and deployment but also greater risk that the choices will prove sub-optimal in the near term and threaten early return on investment (ROI). In the long term, however, operators believe that LTE network infrastructure planning will settle on a common model.

Operators also believe that LTE will ultimately transform metro networking, the role of voice central offices, and the structure of business and consumer services. This means that the most significant greenfield/brownfield network issue may be whether the operator is deploying LTE as an adjunct to a common carrier role and a successor to TDM-based services, or whether LTE is the model of its service present and future.

About the author: Tom Nolle is president of CIMI Corporation, a strategic consulting firm specializing in telecommunications and data communications since 1982. He is the publisher of Netwatcher, a journal addressing advanced telecommunications strategy issues. Check out his networking blog Uncommon Wisdom

This was last published in October 2010

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