Low band spectrum (400, 700, 800, 900MHz) provides clear improvement to network coverage over high band spectrum (1800, 1900, 2100, 2600MHz) for wireless networks. Low band spectrum can give twice the coverage radius of a high band site while at the same time providing 6-10dB improved signal strength at the same point. The drastically greater coverage provided by low band spectrum may in tern be offset by increased noise levels at peak traffic times. It is best to offset low band systems with corresponding high band implementation of the same system. The two dominant carriers within the United States execute exactly this strategy with a low-band focus on coverage and high band focus on capacity.
Once high and low band carriers are deployed for newer technologies (LTE/WCDMA), various parameter and footprint optimization strategies allow for the proper traffic balancing between carriers of each band. It is with this in mind that each operator should determine means to have their networks of greatest importance within their available low band spectrum. This will allow for minimal OPEX costs for maximum network coverage, improved customer satisfaction for in-building and general coverage and allow for the high band spectrum for capacity constraints in urban or high traffic areas.
Operators should consider moving quickly away from legacy systems that occupy low band spectrum for the simple reason that these are typically lower revenue generating users. Subscribers with next gen smartphones have a significantly higher ARPU and should be given the greatest network experience available. In order to redistribute the low band spectrum that is already being utilized by legacy systems, the operator must consider a variety of items in planning out potential and capital expenditures to deliver the final product.
- Technology: Determine technology and desired carriers/block sizes for redeployment. UMTS, LTE, etc
- Spectrum: Determine continuous blocks of spectrum to re-allocate. Considering at least 5MHz blocks and how to add spectrum blocks as users upgrade from legacy systems to the next gen networks.
- Handsets: Work with handset manufacturers to ensure desired spectrum bands are available for desired technology. Not only do new handsets need to cover it, but if the existing user base does not have handsets capable of utilize the new technologies on the re-allocated spectrum, all the capital expenditure will not generate any revenue until they are available.
- Equipment: Capable radios, amplifiers, RHA/MHAs, TMAs, etc. The capital requirements to retrofit existing sites to support the deployment.
- Antennas: Available ports on existing low band technologies or combining as required. Additional antennas may be required for MIMO and other LTE-A considerations.
- Design: Network design for utilizing of sites from existing network. Potentially only 60-80% of sites are required to meet design requirements and allow for reduced interference and cell overlap inefficiencies once acive.
- 3GPP: Request classification of spectrum blocks for LTE carrier aggregation (if not previously set. Not required if not planning LTE) Ensure your spectrum is included in planning for the long term migration to LTE/LTE-A and the benefits coming from a single network infrastructure.
- Government: Ensure classification of spectrum for that technology/use is allowed within the spectrum lease.