The following quoted text (beginning at the bullet, below) is taken from the statement of prior art in US Patent 5,673,322 entitled System and method for providing protocol translation and filtering to access the world wide web from wireless or low-bandwidth networks and filed in 1996 by Bell Communications Research.

For those of you who have always wanted somebody to just tell you how the Web works without all the technological jargon, this statement of prior art comes as close to your wish as is possible. This is a wonderful overview of where the Internet, and then the Web, came from without being technologically overwhelming. Ignore the references to low data speeds and data transmission rates, and don't let this fool you into thinking that the fantastically faster data speeds of today makes the following discussion irrelevant. The invention (not presented here) sought by Bell Communications Research relates to an improved WWW interface with protocol translation, security and automatic configuring features that is just as relevant today to as it was in the mid-1990s.

• "For fifty years, people have dreamed of a universal information database--data that would not only be accessible to people around the world, but organized such that related information is easily discovered and so that the most relevant data for a particular need is quickly found and accessed by a user.
  
  In the 1960's, this idea was explored further, giving rise to visions of a "docuverse" that would revolutionize all aspects of human-information interaction, particularly in the educational field. Only recently has the technology started to fulfill these visions, making it possible to implement them on a global scale.
  
  The Internet has evolved through a cooperative effort by universities, corporations and government. Years ago, the Defense Department started interconnecting the computer networks of universities, private organizations and sometimes corporations with whom research was being conducted. This network of networks has, over time, evolved into a global network commonly referred to as the Internet or the World Wide Web (WWW). The official description for the WWW is a "wide-area hypermedia information retrieval initiative aiming to give universal access to a large universe of documents."
  
  As the WWW became more popular and subject to wider public use, the Department of Defense curtailed its involvement. Today, many government-funded links on the Internet have been turned over to commercial enterprises that maintain the interconnection of Local Area Networks (LANs) between universities, companies, etc.
  
  Though the WWW is proving to be an extremely valuable resource for corporate enterprises (for communicating via electronic mail (e-mail), accessing information on-line, etc.), corporations are concerned about the security of their intellectual property, trade secrets, financial records and other confidential information stored on their computer networks. There is also concern about electronic vandalism -- unauthorized access of a computer network over the WWW for the purpose of destroying or distorting computerized information.
  
  [Original image modified for size and/or readability]In response to these concerns, some connections to the WWW have been protected with "Network Security Firewalls." As shown in FIG. 1, a firewall is commonly a specific piece of hardware and/or software bridging the connection between a private computer or computer network (LAN) 10 and the WWW 12. The main purpose of a firewall is to screen data traffic into and out of the network that is to be protected. If a network intruder is detected, the firewall has the capability of sifting through the data traffic and disabling the intruder's access. In early forms of Internet firewalls, it was generally difficult to ascertain which data traffic was good or bad, i.e., relating to a corporate user or an intruder. This created a problem for corporate users (inside the corporate LAN) of Internet applications, such as File Transfer Protocol (FTP), because their applications would sometimes get incorrectly blocked by the firewall. The firewalls needed more intelligence about application data traversing a firewall so that desirable traffic was not hindered.
  
  Internet engineers designed "proxy" services on Internet firewalls to meet this need. These proxies are computer processes that completely understand specific applications like an FTP application. It became a straightforward matter for network administrators to add multiple proxies to the firewall system based on the type of applications the internal corporate users wanted to execute. For example, WWW browsers (described below) would use a Hyper Text Transport Protocol (HTTP) proxy to transfer Hyper Text Markup Language (HTML) documents.
  
  To facilitate use of the WWW, "browsing" software 6 was developed. Browsers, such as the popular Netscape.TM. and Mosaic.TM. browsers, allow WWW users to browse information available on computers linked to the WWW. A related invention by the assignee, described in U.S. patent application Ser. No. 08/309,336 (hereinafter "the '336 application), provides users on computer networks with a consistent means to access a variety of media in a simplified fashion. Making use of browsing software, the invention of the '336 application has changed the way people view and create information--it has created the first true global hypermedia network.
  
  [Editor's Note: U.S. patent application Ser. No. 08/309,336 was issued in 1998 as US Patent 5,742,905 entitled Personal communications internetworking]. 
  
  One responsibility of an HTTP proxy is to receive requests from browsers or software applications 6 within the protected network 10 and relay those requests to the WWW 12. The proxy also monitors access to the protected computer or network 10 from the WWW 12. Thus, the proxy 4 can allow a system administrator to monitor information and requests flowing between the protected network 10 and the WWW 12. If illicit activity is discovered, the proxy 4 can interrupt the connection to the WWW 12. This proxy-driven firewall 2, 4 allows corporations and those with similar concerns to make use of the valuable resources of the WWW 12 while maintaining a degree of security.
  
  To effect links between computers and software applications across the WWW, protocols have been developed to govern the transmission of computerized data. A protocol organizes data to be transmitted over the WWW in a standard way recognizable by the receiving computer. There are seven layers in the open systems interconnection (OSI) model of a computer protocol. Each layer adds additional organizational capabilities that facilitate the transmission of data.
  
  Internet Protocol (IP) is the third layer in the OSI model and the basic "language" that is spoken on the Internet. The fourth layer, Transmission Control Protocol (TCP), is a more specialized protocol contained in IP. To use the WWW, a computer must be able to communicate using a protocol that incorporates IP and, consequently, TCP.
  
  The WWW and technologies surrounding Internet access have seen explosive growth. Many companies have evolved to allow subscribers access to the WWW using standard telephony. A group called Internet Service Providers (ISP) represents many of these service providers.
  
  A promising area for further expansion of Internet access is wide-area wireless data networks. The wireless networks include cellular digital packet data (CDPD, provided by cellular carriers), circuit-switched cellular networks, such as the Mobitex.TM. network (provided by RAM Mobile data in the U.S.), the Ardis.TM. network, and a host of emerging national wireless data providers.
  
  All of the listed data network providers offer traditional Internet Protocol (IP) service and are capable of integrating with the WWW. The data speeds range from 4,800 to 28,8000 bps and have latencies that range from milliseconds to 10 seconds.
  
  Despite the popularity of the WWW, there are still technical and security issues that must be overcome in accessing the Internet. Some of these problems are particularly acute for wireless systems trying to access the WWW.
  
  Problem 1
  
  The first problem is caused by data latency (described in more detail below). Data latency refers to the time delays created by multiple hops and slow links as data travels across various nodes within the WWW. This particular problem is exacerbated when the WWW is accessed using a wireless modem. Most wide area wireless, and some wireline, data networks were not originally designed to support the TCP/IP protocol. Latencies are increased even further by encapsulating IP data into the networks' original data protocols.
  
  When TCP is organizing data for transmission over the WWW, it breaks the data into discrete "packets" of information. TCP then transmits the individual packets. Each packet includes instructions to the receiving system for reassembling the packets into the complete data structure being transmitted. Each packet also includes a cyclic redundancy check that allows the receiving system to check that the packet was not corrupted or broken up during transmission.
  
  TCP is typically configured to transmit a number of packets and then wait for a confirmation from the receiving system that the packets have been received properly. The amount of time required to transmit a data packet and receive confirmation of its arrival is known as the "latency" of the system.
  
  If TCP does not receive confirmation that the data packet was properly received, it will assume that the packet was lost during transmission and re-transmit the packet. If the latency of the system gets too high, TCP will assume, prematurely, that the packet was lost and flood the network with re-transmissions of the same data packets before the original packets reach their destination. This is also a problem because many service providers charge users per data packet transmitted. If TCP is flooding the system with unnecessary duplicates of packets still in transmission, the cost to the user will be greatly increased. Thus, TCP cannot operate properly over a connection with a high latency. If the latency of the system exceeds approximately 3 to 5 seconds, TCP will begin to malfunction.
  
  When the WWW is accessed over standard phone lines that do not support TCP, the TCP datagram must be encapsulated (i.e., translated) into a form that can be sent over the telephone line. The datagram is then unpacked and used by the receiving computer. While this approach works, it adds to the latency of the transmission.
  
  A further problem with accessing the WWW using a wireless modem is the increased latencies that are introduced by the wireless network. A general trend is the wider the area served by a wireless data network, the lower the bandwidth (in bps) of the transmission. For example, present wireless communication systems in use in the United States are capable of transmitting 4,800 bits of data per second. This results in latencies up to as much as 10 seconds.
  
  Related art on wireless WWW access exists at: 1. Carnegie Mellon University's Information Networking Institute, Wireless Andrew Initiative. 2. Rutgers University's Winlab, Dataman project. 3. University of Washington's CS&E, Mobisaic. 4. Xerox's Palo Alto Research Center, PDA and virtual office computing concepts. 5. Computer Networks & ISDN Systems Volume 0028, Number 1-2 ISSN:0169-7552, December '95, "PDAs as Mobile WWW Browsers", Gessler S., Kotulla A. 6. General Magic's, Magicap OS version of a WWW browser with enhancements for Telescript agent technology.
  
  All of these projects and papers either require the modification of a browser, specification of new protocols (still based on TCP), or defining generic inter-networking specifications for connecting wireless and low-bandwidth networks to the Internet for WWW access.
  
  Thus, there is a need for a method of translating TCP in connections over high-latency wireless and wireline networks.
  
  Problem 2
  
  A second problem is that current WWW access software does not provide standard mechanisms for compression, encryption, or filtering. Compression entails decreasing the size of transmissions of data over the network without changing the content of the information. Most proposals for compression support require external utilities from the browser to decompress the data, and then return usable output to the browser through the use of Multipurpose Internet Mail Extension (MIME, Nathaniel Borenstein et. al RFC 1521) types.
  
  Encryption is the coding of data transmissions. Encryption helps to provide security since encrypted data transmissions are much more difficult for an unauthorized party to intercept and access. Unfortunately, it is unlikely that generic, open standards for these desirable services could be created to support all WWW client requests. Standards are evolving for encryption in WWW software (i.e., Secure Socket Layer (SSL)). However, at current levels of computer hacking, it is unlikely that any open standard for encryption will be able to maintain integrity for long.
  
  Most advanced browsing technologies, therefore, have installed proprietary encryption schemes and are only capable of working between a WWW server that supports the encryption scheme. This option goes against the open standards design of the WWW.
  
  Filtering refers to global control of a WWW response based on data size, type, or some other characteristic whereby a user can customize the receipt of data. Work is being done in this area through WWW search engines, specialized caching utilities on advanced browsers, etc.
  
  The filtering referred to here is a global safety net for unwary users that could potentially misuse a wireless/low-bandwidth data network by requesting too much data, retrieving spurious information, or some other unwanted side effect resulting from a WWW request. For example, a user may request a data object from the WWW that a user is not aware is extremely large, and perhaps costly, to transmit. AS a safety net, the user may configure a filter to automatically prevent a particular request from being executed.
  
  Thus, there is a need for an implementation of compression, encryption and filtering features in a WWW interface.
  
  Problem 3
  
  A third problem exists in that there is no standard way for WWW access software to receive asynchronous or unsolicited updates from the network. Existing browser technology is client based. The most popular browsers, such as the Netscape.TM., Mosaic.TM., Lynx.TM. browsers, as well as other less popular browsers, require users to initiate some form of request before response data will be delivered to the respective browser.
  
  For example, it is desirable for a company providing access to the WWW to be able to remotely configure a subscriber's WWW access system from within the network. Since regular browsers do not offer this feature, subscribers must configure and update their access software manually. This may require the support of the service provider through a traditional voice customer support line or custom agent software on the user's host system.
  
  Thus, there is a need for a WWW interface that can receive and implement unsolicited transmissions from the network or service provider, particularly to automatically configure software for accessing the network."

I am filing this entry in the Reference Library to this blog.