UMTS in 900MHz is finally seing light

ARCEP announced yesterday that it has authorised Orange France and SFR to deploy UMTS technology in France in the 900MHz band. ARCEP also proposed that Bouygues Telecom should reuse the 900MHz band for 3G. According to the regulator, the mobile operator said that it would deploy UMTS in the 900MHz band by the end of 2009 and that it would request modification of its authorisation when it is necessary.


UK regulator Ofcom has already opened a consultation on the future of the 900MHz band, currently allocated to Vodafone and O2 for their 2G services, and has suggested that a technology-neutral auction might be in order for 2009.


So, why should we be happy with 900MHz UMTS as opposed to 2100MHz UMTS:

• The increased frequency reduces cell range, resulting in a more costly network rollout and makes achieving GSM like coverage (>90% population) very challenging. Additionally, with the rapid roll-out of HSDPA (an evolution bringing broadband like speed to UMTS) and its less robust, higher-order modulation scheme (16QAM), building penetration from macro deployments becomes an issue.
• W-CDMA (UMTS) in the 900MHz band achieves a 60 per cent reduction in the number of cell sites required to serve rural areas, and can deliver improved quality of service in urban areas by enhancing in-building penetration by 25 per cent.
• 900MHz is a good frequency for building penetration and decent range, and is used in rural areas where the small-cell-site advantage of 1800MHz is less applicable.
• Signal coverage of 2 – 4 times the coverage in the 2100MHz band, resulting in a reduced number of base stations required
• Improved indoor coverage in urban areas. A 2006 study showed a 25% improvement in in-building penetration
• Added potential for re-use of existing GSM base stations, antenna systems and feeders if deployed within existing GSM sites
• Lower power consumption, since the RF power amplifier (one of the largest electricity consumption item in a Node B) efficiency is much improved