para [0018]-[0019]: [0018]These problems and others are solved by the improved method and apparatus according to the invention. A presently preferred first main embodiment of the invention is a system including a virtual session manager (VSM) for establishing and maintaining a sessionless communication path with a first data processing device (e.g., a mobile client) on the one hand and a session-oriented communication path with a second data processing device (e.g., a host system). The session-oriented communication protocol (including network and application layer protocols) with the host system permits remote access to, e.g., LAN-based applications, while the virtual session, via a sessionless-oriented communication protocol, between the VSM and remote (i.e., coupled via a tariffed network or connection) client permits this access to be carried out without the expense of a dedicated/circuit switched connection. [0019]In a second main embodiment, a prestage filter stage is provided for applying user-definable filter parameters (e.g., reject, pass, or granularity filters) on data being transferred between the remote communication unit and communication server. For downloading, e.g., email from a host post office, a communication server controller preferably either forwards the filter parameters in a query object or message to the post office to apply and return qualified mail, or the communication server receives all unprocessed mail and applies the filters locally, only acknowledging as processed that mail which is qualified. For uploading, e.g., email from a client, a client controller applies an upload prestage filter so as to retain all filter rejected mail, while transmitting mail passing the filters. Thus, only desired data transfers (i.e., those meeting user defined filters) are communicated over the expense-bearing networks between the remote unit and communication server. para [0025]: [0025]FIG. 2 illustrates an alternative communication system 200 embodiment of the present invention. A first client, a mobile end system (M-ES) computer including a user device 201, is in communication with a base station (BS1) 218 of a wireless communication system. This base station 218 is coupled, e.g., on a same bus or via bridges/routers, to a communication server 220 which includes VSM 230. An electronic mail (email) post office is coupled locally to VSM 230, either as another program running on the same communications server 220 or located on another server 240 of the communications server's 220 LAN/WAN. It is not important, however, where the post office is located for purposes of operation of the VSM 230, as is illustrated by other application hosts B and C 255, 260 being in communication via other networks such as a public data network or public switched telephone network 250. In fact, the same user 201 could be concurrently coupled via the VSM 230 to, for example, a local email post office 240, a remote client-server host 255, a further database host server (not shown), an administrator host server 260, a multimedia host, a voice processor, etc. It should be understood that for purposes of this application, a first device or component is responsive to or in communication with a second unit or component regardless of whether the first and second units are directly coupled or indirectly coupled, such as via intermediate units, including switches that operatively couple the units for only a segment of time, as long as a signal path can be found that directly or indirectly establishes a relationship between the first and second units. For example, the client computer 105 is in communication with the VSM server 110 even though intermediate system (e.g., a router or switch) 125 and a packet network 130 having multiple switches etc. are disposed between the user device 105 and VSM server 110. para [0033]: [0033]Turning now to FIGS. 4 through 6, a presently preferred embodiment is shown for prestage filtering data for transfer between the different functional entities of the wireless communications system of FIG. 2. This typically begins with the generation of a query object or message at the communications server (step 406). This object/message may be created in response to a preceding client generated message (e.g., a request generated when clicking on an application button requesting updates, executing the mail application, etc.), or in response to settings in the client profile. However, after updating the active client profile/object for an active client application, the query manager is preferably programmed to send query objects at predetermined intervals for each application being run by each active client, the intervals varying depending on the application type or administrator preference (e.g., for mail about every 10-30 seconds or longer). Alternatively, the intervals could be user specified via the client profile, for example to shorten the query intervals for time critical applications (e.g., for emergency services or "real time" applications), or lengthen the intervals when less frequent updates are desired (e.g., to conserve on traffic expenses for updates to a rapidly changing, but non-time critical, group-ware file or document).