Porting audio is tricky, particularly if your MIDlet has extensive reliance
on player lifecycle events. Also, there is no support for pitch, tempo or
volume controls and the current state of the presenter cannot be queried
7.7.11 Game Development
Although you can build altruistic little GUI applications, such as Cellulite ,
the real money is in game development. It was the games market that
drove mobile development technologies in the first place and it all started
in Japan. Needless to say, this market is the largest and most dynamic in
the world. For a great review of how easy it is to build DoJa games, check
out the game development tutorials on the DDN. 13 We talk a lot more
about games in Chapter 8, so we will say no more here.
7.8 DoJa 5.1 Profile
The FOMA 905i series of handsets, released in November 2007, was the
first handset series to implement the new DoJa 5.1 profile. Series prior to
this (specifically 903i, 904i, 703i, and 704i) used the only slightly older
DoJa 5.0 profile.
One of the impressive features of NTT's FOMA 3G technology is
its high-speed data communications. The network communication size
for HTTP connections is 80 K up and 150 K down (as opposed to the
10 K up and 20 K down for Personal Digital Cellular [PDC] handsets - a
2G standard developed and used exclusively in Japan) 14 with download
speedsofupto3.6Mbps. 15 This, combined with NTT's flat-rate data
charges, means that mobile application developers targeting this market
have the freedom to design applications that
take full advantage of
high-speed, low-cost data transmission.
The i-Appli development environment comprises four layers of APIs.
The first layer is the Java ME CLDC API, on which DoJa is built. This is a
point of commonality with the MIDP architecture where there is a larger
English-speaking development community. The remaining layers are the
i-Appli Basic API, the i-Appli Optional API, and the i-Appli Extension API
(see Figure 7.8).
The exact boundaries between the Optional and Extension APIs are
not clear, and it is usual for the DoJa documentation to lump these two
14 See [NTT DoCoMo 2007]
15 3.6Mbps is the maximum receiving data rate when using a FOMA HIGH-SPEED
compatible handset in a FOMA HIGH-SPEED area (see www.nttdocomo.co.jp/english/
service/function/high speed ).