Enterprises are starting to want to tie mobile phones into their converged voice/data enterprise networks so that cell phones (including dual-mode cellular/Wi-Fi handsets) become another "extension" of a company's PBX. The goal is getting a single business number to reach users wherever they are and, if a call must go to voicemail, to leave them with just one mailbox to check.

The most action on this front has been in enterprise-based servers and appliances, accompanied by mobility software for the client devices. Among the companies offering or in the process of building enterprise-centric products to unify phone networks:

  • Ascendent Systems (purchased by Research In Motion in March)
    Uses dual-tone multifrequency (DTMF) as the lowest-common-denominator technology so that its system can also reach non-IP phones. Is working on an integrated Ascendent/RIM BlackBerry Enterprise Server (BES).
  • Avaya
    Extends some of its Communications Manager IP PBX functionality to Nokia Series 60 cellular phones (see also Motorola).
  • Cisco
    The Mobile Connect application for the Cisco Unified MobilityManager server directs incoming IP calls from the enterprise IP PBX (a Cisco CallManager) to up to four different designated client devices. Unanswered calls end up in the user's Cisco Unity unified messaging system.
  • DiVitas
    The start-up is developing an appliance for mixed-mode networks and phones. The company recently announced that it has interoperability-tested its platform with Symbol Technologies wireless LANs and that it is partnering with AirMagnet to build
    security into the voice-over-Wi-Fi component of its forthcoming products.
  • FirstHand Technologies
    Formerly SIPquest. Its "PBX-extension" server and client software is generally sold to PBX and other equipment makers and then resold to enterprises through the equipment-maker's own label.
  • Motorola
    Makes the Enterprise Seamless Mobility server, which handles Wi-Fi-to-cellular handoffs on an enterprise's premise, and continues to test the Motorola CN620 GSM/802.11a handset (now slated for a redesign, however). IP PBX-maker Avaya makes the server component of the solution that extends the IP PBX to the
    mobile phones.
  • Orative
    Touts cellular network-agnosticism. Supports cell phones running Symbian, BlackBerry and BREW mobile operating systems. At this juncture, provides the IP PBX and related calling, presence, and messaging applications itself, rather than extending these integrated communications features from existing PBXs.