Japan’s Softbank (formerly Vodafone Japan) also owns an ISP (Yahoo Japan) and bought Japan Telecom in 2006. They are the No.1 supplier for ADSL broadband services in Japan. They use 3G UMTS technology (i.e. part of the GSM family), but there is no GSM network operator in Japan. Visitors can roam onto Softbank's network if they have a 2G/3G capable phone and a subscription with a GSM network operator elsewhere.
A key concern was the regulatory requirement in Japan for all cellsites (including femtocells) to be installed by a trained technician. This has now been relaxed but Softbank typically continue to send a technician to oversee installation and correct operation.
Softbank were one of the first to setup a femtocell trial in 2007 to evaluate the currently available femtocell products, but deferred widespread commercial deployment. At that time, the operator believed that interference issues with macrocells remain a technical block, and therefore femtocells were still 2 to 3 years away from solving capacity problems. These views subsequently evolved and a commercial deployment took place.
- They initially required femtocells to solve coverage issues, especially for their enterprise customers with rural branch offices
- They believe there are still cell-to-cell interference issues with the macrocellular network
- Softbank believe there are lots of good ideas which could form the basis for a solution, but these may take 2-3 years to be realised
Over subsequent years, they determined that these issues has been resolved, especially for indoor small cells. Unusually, the operator chose an IMS core network architecture, which is relatively uncommon. Japanese industry has been promoting IMS alongside LTE, the next generation of radio interfaces for mobile phone systems. It also fits in more closely with their broadband DSL and ISP assets.
The Softbank CEO further outlined their views in November 2009, highlighting that LTE on its own would not be enought to satisfy mobile broadband capacity where 50% of data usage is in the home during peak periods. Instead, he believes WiFi has a huge role to play.
Softbank are also reported to be deploying femtocells for rural and outdoor coverage, using NEC/Ubiquisys products connected through a shared satellite backhaul from IPSTAR.
Softbank then made a bold move, apparently driven by their senior management, to promote and supply femtocells more proactively. An offer of free femtocells and a free dedicated DSL line was given to any customer claiming poor indoor coverage in their home or retail outlet. This was partly intended to dramatically rebalance the perception of poor coverage in some parts of the country. Softbank had around 98% population coverage compared with over 99% for their larger competitors. The offer had to be extended by popular demand.
- Product: Ubiquisys femtocell
- Data: 14 Mbit/s downlink
- Calls: Up to 4 concurrent voice or data calls
- Broadband: Free dedicated DSL broadband provided
- Installation: By qualified Softbank engineer