Schoolar: LTE could be just what 450 MHz needs

Daryl Schoolar ovum

Daryl Schoolar

450 MHz has been something of a white elephant in the wireless community. Its propagation ability makes it a valuable commodity for trying to cover large, lightly populated areas. At the same time the limited spectrum availability in this band hinders performance, and revenue potential of building devices or deploying services at this band have so far limited the development of an ecosystem. Sure there are CDMA deployments in that band, but they haven't really make 450 MHz a hot market. Ovum estimates CDMA450 users represent well under 10% of the tal CDMA user base. However, LTE450 (LTE at 450 MHz) might finally change all of that.

LTE holds real promise for operators looking to get the most out of the 450 MHz band. First of all LTE has greater spectral efficiency then CDMA thus improving data performance of the network. CDMA450 has been mainly used for voice services. There was some thought CDMA Rev. B could be the answer to 450 MHz data woes, but that technology hasn't taken hold.  Networks using the 450 MHz band need a stronger ecosystem, which LTE can provide.

No doubt the LTE ecosystem has a brighter future than that of CDMA. And this goes for LTE450 versus CDMA450. There is growing support for LTE450 from the chip, device, and network vendors. Alcatel-Lucent promotes LTE450 as a way to deploy public safety networks. ZTE has developed a dual-mode CDMA/LTE radio head to help operators transition to LTE.  Other vendors supporting LTE450 are Huawei, Qualcomm, Samsung, and Mediatek. Applications for LTE450 will include not only fixed line replacement and mobile broadband, but machine-to-machine communications as well.

Another factor in the success of LTE450 of course depends on operator interest. Per the CDG (CDMA Development Group) there are 115 CDMA450 operators across 60 countries. As the CDMA development path is coming to an end, those operators area all possibilities for LTE450.  Already we have two operators appearing to make that move from CDMA to LTE.

Ukko is a Finish operator.  The company currently has a CDMA450 network but is making the move towards LTE450. During the transition the mobile operator will be updating 241 cell sites.  Ukko expects the new network will be able to support 15 Mbps in the downlink. This is a far cry from what users see on other LTE networks, but still an improvement over CDMA. To help migrate the customer base Ukko will be issuing new CPE to them. Handheld and personal hotspot devices (MIFI) are expected in 2015.

The Russian government has given Rostelecom's subsidiary SkyLink permission to trial LTE450. The trial is taking place in the Kostroma region, a mainly rural part of Russia. The operator has reported that peak speeds on the network have reached 30.6Mbps, and that the base station signal has a range of 20km.

No doubt the big market that can have a major positive impact on LTE450 will be Brazil. Brazil's Telecommunications Research and Development Centre has been one of the forces behind the standardization of LTE450 under 3GPP Rel. 12. In April 2012, Anatel (National Telecommunications Agency) bundled together the auction of 450 MHz spectrum with that of 2.6 GHz for the deployment of LTE. The bundling of the bands was done to generate interest in 450 MHz band, since operators were not expected to bid on it unless it was tied to the more desirable 2.6 GHz band, which already has robust LTE ecosystem support.

In the end, each of the four main mobile operators in Brazil ended up with 10 MHz of 450 MHz spectrum. The auction came with a government mandate for rural broadband coverage of 30% by mid-2014, 60% by end-2014, and full coverage by end-2015. Although operators don't have to use the 450MHz band for rural coverage, given the nature of the western Amazon rainforest of that country, the advantages of LTE450 are obvious. Field trials carried out in Brasilia have achieved a 19 Mbps downlink and 6Mbps uplink, and trials in the area of Sao Paulo have covered six cities using a single BTS.

LTE450 will probably have a head start in Brazil, despite plans to auction spectrum in the 700 MHz band in August. The Brazilian Ministry of Communications says that not only will LTE be more expensive to deploy at 700 MHz, but the process is also likely to be drawn-out and complex, and cannot commence before late 2015 due to the need for broadcast companies to first vacate the spectrum.

The adoption of LTE450 won't come without challenges. For one, despite the growing ecosystem there still aren't devices. Once Rel. 12 is finalized this year that situation should improve. Another challenge will be how operators migrate users from CDMA to LTE, especially when many of them don't have much spectrum. With voice being a big part of CDMA450, VoLTE will be important to the migration from CDMA to LTE.  While these aren't small challenges, operators looking to best utilize their 450 MHz spectrum should still find LTE to be their best option. I will just take a few years before that option can be fully realized.

Daryl Schoolar is Principal Analyst of Wireless Infrastructure for Ovum. Daryl's research includes not only what infrastructure vendors are developing in those areas, but how mobile operators are deploying and using those wireless networking solutions. Contact him at [email protected] and follow him at @DHSchoolar.