LTE Migration Strategies: Over-the-Air Provisioning Considerations
The pressure faced by mobile network operators to upgrade to Long Term Evolution (LTE) is intense, and operators worldwide are announcing plans to transition to this next-generation technology. However, the LTE ecosystem is still immature, and legacy networks require continued support, so an immediate move to LTE may not be truly necessary. For many CDMA operators, migration to LTE in a series of logical steps rather than a single leap from 2G or 3G networks may make more sense, enabling them to maximize investment in their existing infrastructure.
There are several crucial considerations for operators taking a phased approach to LTE deployment. Key among them is how device provisioning and parameter administration needs will change as the network evolves. Operators have the option of supporting devices with smart cards known as Removable User Identity Modules (R-UIMs) as an interim step between the simplistic updates made directly on handsets and those made on more advanced LTE devices. A robust Over-the-Air (OTA) provisioning solution that can support multiple technology generations is crucial for minimizing the overall expense and network complexity associated with activation and provisioning functions.
LTE Transition Options
With 248 operators in 87 countries now investing in LTE, the Global Mobile Suppliers Association calls it the most rapidly developing mobile system technology to date. In fact, the supplier group estimates that 185 operators currently have firm commercial LTE network deployments either planned or in progress — a 64 percent increase over last year — and 63 operators are currently undergoing LTE trials, tests or studies. The group forecasts that 103 commercial LTE networks will be deployed by the end of 2012.
Despite compelling reasons for adopting LTE — including the promise of increased bandwidth for voice and data services, lower operational costs and new revenue opportunities — a transition to LTE is a costly proposition for operators that already have made substantial investment in legacy networks. Infrastructure spending on LTE is projected to grow from $1.5 billion in 2010 to $27.9 billion by 2014, a compound annual growth rate of 107.5 percent, according to IHS iSuppli Research. In the short term, operators will be challenged to provide voice-over-LTE service given an immature ecosystem and limitations of the current device pool. In addition, subscribers will continue to utilize 2G and 3G devices for the foreseeable future. As a result, operators that leapfrog directly from 2G or 3G systems to LTE for data services will still require dual systems for a significant period of time.
Rather than moving directly to LTE, operators can instead upgrade their existing infrastructure to realize incremental benefits. For example, operators with a CDMA 1X network may find it more cost effective to migrate to EV-DO Rev. A and then to EV-DO Rev. A+ or B to optimize their 3G investment. In doing so, they can benefit from significantly faster data rates and performance improvements prior to a full LTE transition. This strategy also enables operators to wait for a more advanced LTE ecosystem, including wider availability of devices with volume pricing, as well as voice-over-LTE stability, before making a complete transition.
A critical component of any migration strategy is an OTA solution that can support operators as their networks evolve. OTA device programming is used primarily for new account activation, as well as handset upgrades, Preferred Roaming List (PRL) updates and other important parameter changes. OTA configuration has become increasingly important for operators as mobile phones have become more advanced and new updates and services have been introduced. OTA solutions enhance customer retention by delivering convenience for end users, who avoid time-consuming trips to wireless stores for updates to their devices.
CDMA operator device pools typically include handsets requiring Electronic Serial Number (ESN) and Mobile Equipment Identifier (MEID) programming directly on the units. Such devices call for relatively simplistic OTA functions. In contrast, the new generation of LTE devices features smart cards known as CDMA Subscriber Identity Modules (CSIMs). These removable cards enable subscribers to maintain the same phone number across different devices simply by swapping the card.
To support CSIM-based devices, operators require a much greater degree of provisioning complexity, as well as a robust security and card management strategy. As a result, operators moving to LTE must be prepared to train their staffs — including sales personnel, customer care representatives and engineering staff — to support these advanced OTA features, and a robust OTA solution must be in place to provide the tools and reporting needed to support these tasks. This can represent a dramatic shift for operators in terms of both required time and resources. Also likely is the need for operators to continue provisioning earlier generation devices without CSIM cards. Not all OTA systems can support both early generation and LTE devices, so two separate OTA platforms may be required to support the full range of device types.
When upgrading current CDMA networks, operators have the option of supporting devices with Removable User Identity Module (R-UIM) cards as an interim step prior to introducing CSIM-based devices. Both R-UIM cards and CSIMs have elementary files, which contain security-related procedures and data storage items that permit the basic management of handsets, as well as the delivery of user features and services extending beyond traditional IS-683 provisioning. Examples include updates for SMS parameters and WAP browser features, as well as supplemental features, such as call forwarding when a number is busy and call forwarding to a new number that operators can update.
R-UIM-based devices, widely used outside of the United States, can be viewed as an intermediate step between provisioning directly to handsets and updating CSIMs. By supporting devices with R-UIM cards, operators can take advantage of the opportunity to familiarize staff with elementary file updates prior to the introduction of more sophisticated LTE devices. Offering R-UIM-based devices also enables operators to benefit from the Open Market Handsets (OMH) initiative, an effort by the CDMA Development Group (CDG) to increase device variety and create new distribution channels within the CDMA ecosystem. OMH changes the CDMA paradigm by enabling subscribers to purchase and use an OMH device in any OMH-compliant operator network. OMH requires all operator- and subscriber-specific provisioning to be moved from the device onto the R-UIM card.
To eliminate the need for dual OTA platforms, operators should seek a provisioning solution that supports the full range of device types, including earlier generation as well as smart card-based devices. OTA solution providers like Interop Technologies are developing end-to-end solutions for CDMA operators transitioning to LTE.
For many operators, strategic upgrades to legacy networks will provide a more cost-effective evolution to LTE than a direct transition to next-generation technology. By migrating in a series of logical steps, operators can maximize investment in their existing infrastructure, enabling them to benefit from incrementally faster data rates, as well as improved efficiency and capacity. A robust OTA solution that can seamlessly manage all OTA functions — from legacy CDMA networks through the LTE transition — is critical for operators to minimize the expense and complexity associated with device provisioning.
Chip Stevens is the product manager for Over-the-Air Provisioning Solutions at Interop Technologies.