V.92 - The next standard. Special Report

V.92 - Special Report (Updates here)
+ V.44 & V.59

What are V.92, V.44 & V.59 - The next modem standards
What V.92 is supposed to offer:
Increased upstream rates - up to 48k by using a PCM stream through an a/d conversion. [Still, only 1 a/d conversion is required: if you have trouble getting 56k rates with V.90, there will be no improvement.] As of September, 2003, most server-side modems do not support PCM upstream at all, and those that do - 3Com & Patton - support a maximum upstream rate of 33.3kbps - less than the maximum V.34 upstream!
Quick Connect - The time to establish a connection may be reduced with faster handshaking.
Modem On Hold - Allows modems to stay connected 'on-hold' while you take an incoming call-waiting call, or initiate an outgoing voice call. (Works only if V.92 server modem is configured to allow this feature.)
What V.44 offers:
Improved data compression - Typically up to 6:1 data compression compared to 4:1 max with existing V.42 compression standard. Note that software modems will be able to take advantage of this, but most serial ports limit maximum transfer rate to 115.2k - which limits data transfer to 92.2kbps. See V.44 vs V.42. (Data compression depends upon the nature of data transfer.)
What V.59 offers:
Diagnostic data - This is client-side feature, that allows the modem to hold previous call information in a buffer so an application on the PC can query it for troubleshooting purposes. Adoption of V.59 as a standard may come sometime after adoption of V.92.
More Info on Modem On Hold & V.92: The amount of time you can place your Internet connection on hold while taking another call will be up to your ISP: the V.92 recommendation will permit ISPs to set their modems to wait for 0 - 16 minutes, or, to wait indefinitely. V.92 client modems may include software that will warn the user when the ISP-determined timeout approaches, as well as to display call-waiting caller-id info (requires telco call-waiting/caller-id service). Note that ISPs have an incentive to limit the use of this feature: when a call is placed on hold, the ISP modem remains unavailable to take other calls. The ISP may need to add more modems to maintain quality of service if this feature is enabled.
More on V.92 Upstream: The V.92 specification will allow a PCM upstream at rate from 24,000bps to 48,000bps. The rate will increment in steps of 1.333k as in V.90. So, upstream rates could be 24k, 25.3k, 26.6k, 28k, etc. While the specification allows a 48k rate, it may be as elusive as 56k with V.90.
More on Quick Connect: V.92 modems will remember connect rates on past connections by storing data about those connections in a buffer. The modem will compare line quality variables as it dials in to a server modem with those in the buffer, and if a match is found, the handshake starts at the rate previously negotiated. Quick Connect will also be used with Modem On Hold: when a call is switched back to the modem after using the MOH feature, a retrain is required.
The LATEST INFO on V.92: Click here for the V.92 News & Updates page.

V.92 - Special Report (Updates here) + V.44 & V.59

V.92 - Special Report (Updates here)
+ V.44 & V.59