8.2 Infrastructure Needs Me
8.2.1 Computing Realms
Me-centric applications will be running on an aggregate computer that will consist of many distributed individual computers. In order to understand this aggregate, we need to classify these computers into realms (see Table 8.1) so we can think about the kind of software we'll need to build for them. These realms are also
Figure 8.1. Computing Realms
Table 8.1. Computing Realms
The PAN includes all the devices that I carry with me. These could include a PDA and
The MAN includes servers that are distributed regionally to handle load balancing, proxying, caching, content delivery, authorizing, etc. These may be at an ISP, in an enterprise machine room, or at a wireless regional data center (serving several cellular antennas). These computer resources serve a large number of people based either on physical location (cellular network) or based on business relationship (ISP provider or coworkers in an enterprise). The WAN provides servers in large data centers carefully organized to handle large loads for specific applications. This is the way that most Internet and many wireless services are provided today. These computer resources are optimized to scale to huge populations, covering a measurable percentage of the worldwide demand for specific services.
We postulate three ecosystems that are competing for
Both the managed ecosystem and Internet expect me to use WLAN (802.11) and WAN (3G) technologies  ; they differ on business model, not capability.
There are several ways the competition between these ecosystems may
For the users, it should not matter which of the three technical ecosystems they will be using. For them, it will be one unified ecosystem that will make sure that all required services will be available, no matter how they are transported to the