Several manufacturers had some quite spectacular false starts into the wireless VoIP world, with products that suffered from horrible battery life, firmware bugs and very fragile hardware. Have things changed? Which of the current crop of wireless phones and the competing technologies should I choose for my next deployment?
Well, wireless IP phones have come a long way from the early days. Huge improvements in both the technologies involved and the actual implementations have resulted in some really great options for wireless SIP deployments.
First, lets take a look at the two major wireless technologies used with wireless IP phones.
WiFi / 802.11g
Utilizing the same WiFi technology found in your laptop and other consumer electronics gear, WiFI phones connect to your existing WiFi access points around your home or office, as well as some publicly accessible “hot spots”. The phone itself is a SIP client and 802.11g network point combined, and the stationary “base” for the phone is nothing more than a charger.
Pros:
- Uses existing 802.11g wireless access points for connectivity.
- Roaming on the same network, through the use of multiple access points.
- Roaming “off net” at free WiFi hotspots.
Cons:
- Battery life – like almost all devices incorporating 802.11g, battery life still leaves a lot to be desired. You can realistically expect about 2 hours of talk-time, and a day or two of standby time from most current WiFi phones.
- Range – your average consumer/SOHO grade wireless access point with standard antennas provides about 120ft (32m) of coverage in ideal conditions. You may find that places where you want to wander with your phone have patchy wireless coverage.
- Congestion – network quality of service must be very carefully managed, especially with larger installations to avoid voice quality issues.
DECT
DECT (short for Digital Enhanced Cordless Telecommunications), despite being widely used throughout Europe and the rest of the world for more than 10 years, is a relative newcomer to wireless telephony in the United States. With the advent of “DECT 6.0″, these devices can now be used with the FCC’s blessing in the US.
DECT operates at frequencies between 1.8GHz and 1.9GHz and different handsets and base stations from different manufacturers are interoperable with each other. IP phones utilizing DECT technology consist of a base station which bridges the DECT handsets to the SIP world, and allows you to register usually multiple handsets with a single base station.
Higher end SIP-DECT gateways, such as the Polycom KIRK Wireless Server 300 and 600V3 allow upwards of a dozen concurrent calls using a single SIP-DECT base station and multiple DECT handsets.
Pros:
- Wider coverage than 802.11g, with up to 600ft (200m) indoors, and several miles outdoors or indoors using inexpensive DECT repeaters.
- Great battery life – the same kind of battery life you’ve come to expect from regular cordless phones.
- Reliability – by using a separate 1.9GHz frequency which is used only for voice, there is no competition for quality of service or problems with network congestion that exists when sharing a WiFi network with other devices.
- Durability – DECT phones tend to be more durable than their WiFi counterparts.
Cons:
- No ability to leverage existing WiFi installation for coverage.
- No “off net” roaming ability when you’re away from your office.
Conclusions
When we look at the pros and cons of both solutions, it becomes clear that DECT is a clear winner for most applications. With its larger range, significantly increased battery life and increased expandability, DECT should be your choice for wireless IP phones.
Visit Telephonyware for a wide range of both DECT IP Phones and WiFi IP Phones.
