|Expanding Access to Science and Technology (UNU, 1994, 462 pages)|
|Session 4 : Intelligent access to information: Part 2|
|The new world of computing: The sub-language paradigm|
Local area networks (LANs) are a very transient aspect of our computer environment. Once Integrated Service Digital Network (ISDN), Broad-band ISDN (BISDN), and packet switching are fully implemented and installed, file transfers will be sufficiently fast to provide current LAN services between any two telephone-computers. At that time, of course, telephone-computers will have telephone numbers, indeed will be the terminal equipment represented by one's telephone number. Simpler forms of telephone communication, such as voice, email, fax, and electronic messaging, will be subsumed within a much broader spectrum of telecommunication services mediated by the telephone-computer.
When one telephone-computer calls another, pairs of windows are created; one window of each pair appears on the monitor of each computer. One pair of windows is controlled by each participant. The participant controlling a given pair of windows can enter any of his sub-languages; then any of the wide-ranging data and graphics thereby available can be displayed on both windows of the pair. If both participants are authorized to enter the given sub-language, then both can address this sub-language jointly.
For example, in figure 9, a banker calls Bob Moore, one of his clients. The banker shows Moore a bar graph of the changes in Moore's DetEd stock over the last quarter. Moore asks what happened during the previous quarter, and the banker immediately instructs the computer to bring this information forward. The banker shows Moore the implications of the changes he is advocating, and Moore's questions are quickly answered with the supporting data displayed by the computer. A change is made, and its effect is immediately seen by both parties. Once a transaction is decided upon, it is immediately implemented by means of a transaction transfer to the appropriate stock exchange.
We have already shown how a manager can create a sub-language and then authorize his subordinates to be able to enter it, thus creating a common sub-language. A sub-language on one telephone-computer can be entered from a different telephone-computer, provided the requesting person has been authorized.
The combination of basing with the single, worldwide telephone network adds up to a powerful set of capabilities. To see the significance of basing, consider the matter of virtual address space. In current practice, each computer has its own private virtual address space. Data and processes in other files must be brought into this virtual address space by bulk transfer before they can be utilized in calculations. This two-level addressing constitutes a major barrier to the expanded use of computers, in particular to the integration of information resources relevant to the changing needs of applications from the vast resources that are available. That is not how "addressable memory" is utilized in our daily life. Our addressable memory provides an encyclopaedic array of vast amounts of data and process, while only a minute fraction is involved in our immediate considerations.
In the telephone-computer age, there is just one common virtual address space, down to the byte level, for all telephone-computers, for all these resources. This address space is blocked into pages, which are also the packets that move over the telephone lines. International agreements long ago have created a universal address standard, namely the telephone number. When one installs a new telephone and is assigned a new telephone number, one is thereby automatically assigned one's own slice of "virtual memory," one's own corner of the world's address space. Companies that maintain huge data and powerful processing resources have the whole world as their market because they are uniquely identified and reachable through their telephone number. It remains to provide the means of establishing the addressability to these resources. That is the role of basing.
Basing one sub-language on another establishes addressability among the data and process pages that constitute the physical manifestation of these sub-languages. Basing results in the sharing of a common address space whose key element is the addressable page. Therefore, pages whose "home" is on one station are co-mingled with pages from another. This results in a common address space (down to the byte level) across the entire hierarchy of associated sub-languages. Thus it is the sub-languages in such a hierarchy that are "networked," not computers. Such a network may be small and of short duration, servicing an immediate problem. Other networks may be large and stable, hosting an extensive hierarchy of sub-languages. Such "networks" are created, and deleted, by the simple acts of basing and unbasing.
The banker has formed such a network with the various stock exchanges and commodity markets (these being archival stations, discussed below). Since the banker shares an address space and sub-language with these markets, transactions can be completed as a natural aspect of any dialogue with a client.
Here again, in figure 10, is the maintenance professional working on the nosecone radar of a Boeing 747 aircraft, his computer by his side. Consider the networking aspects of this maintenance situation. The computer is networked, in the strong sense of sharing address space, with the Boeing maintenance shops in Seattle, Washington. That is, a sub-language in this computer is based on the Boeing Maintenance sub-language in the Seattle shops. None of the maintenance material is in the computer being used by the maintenance person. First, the identification of the aircraft being serviced is established. In response to a call for a full-colour, annotated image of the radar nose-cone area, the pixel data sets come, via ISDN, from a single source - the high transaction rate server in Seattle. Although some processing is being done locally, all maintenance data and diagnostic analysis are being done in Seattle. The bane of having out-of-date maintenance manuals will be a thing of the past. The addressable page is both the unit of storage and the packet of telecommunication. If the maintenance professional is still puzzled, clicking the mouse on a special icon will establish an immediate conversation with a maintenance specialist at Boeing in Seattle. Both monitors will display the same material, both people can use their mouse to point, and both can have a voice discussion of the problem at hand.
Figure 11 illustrates the point that all of the database records, semantic procedures, utility routines, pixel data sets, etc., are stored as pages, and that only the necessary pages are brought into main memory. We see that by using basing and networking, many if not most of these pages will be drawn from distant stations at the time they are needed.
Each individual item of information in a network of sub-languages has its unique address by which it is identified. The stations whose peripheral memories are the depositories for these items are uniquely addressable by their telephone numbers. Note that it is the hierarchies of sub-languages, with their associated common address space, that are networked, and not the computers. Thus, within a single computer, a person may have many sub-languages, each in its own network. Sub-languages, not computers, are networked; sub-languages have no geographic limits.
In current database technologies, the database consists largely of links from one node of the database to another. The "links" in our semantic net database consist of page addresses. Thus for a network of more than one telephone-computer, the links within a database may refer to pages that reside anywhere in the net anywhere in the world. A database in such a network is "distributed" in an intrinsic way; the basing procedure implements this. The size of a page is 2,024 bytes.
The 64-bit page address has the following structure:
byte offset on a page
2 21 bytes
2 32 bytes
Thus, up to four billion telephone-computers can be accommodated. Each telephone computer may hold two million pages, that is four billion bytes of information. Thus the bound on directly addressable data and processes, the size of the single virtual memory, is 10 19 bytes.
Figure 12 shows a schematic of a typical sub-language network. The inclusion in these networks of large volume servers of archival information will be typical. We have seen this need in maintenance situations. Companies like Mead Data Central in Dayton, ISML, a Houston-based supplier of scientific sub-routines, SpringerVerlag's Beilsteins Handbuch der Organischen Chemie, cookbooks and garden catalogues, the New York Stock Exchange stock closings, and the show records of the American Kennel Club will all be available, page by page as needed by thousands of users. A department store, serving several hundred thousand charge customers, will do so through a high transaction server that makes available all manner of sales material, processes incoming queries and orders, and connects customers to knowledgeable sales personnel.
Figure 13 shows a maintenance professional working for a local service company. The professional's mobile station is in at least two networks: the first, previously illustrated, is with the home maintenance station whose server has all records for the field locations served and all the maintenance information. The second is the dispatcher network. The central dispatcher can see on the map displayed before him the location of all maintenance trucks as they move about the city. When the dispatcher receives a call requesting maintenance service, he can type in the address of the caller and immediately see its location on the map, spot the nearest maintenance unit, click it with his mouse, and talk with the maintenance person directly to coordinate the new service.