When a building or campus’s clock system runs on a Wi-Fi network or Power over Ethernet (PoE) connection, it’s an elegant solution because it solves the need for synchronized time simply and effectively: Each clocks displays the same, precise time that it retrieves using an existing Wi-Fi network or via an Ethernet cable. Both Wi-Fi and PoE clocks are in the IP Network category of clock systems.
Some companies assume that they need to purchase and operate an expensive time server to support an IP Network clock system. As a global provider of clock systems to some of the most recognized companies around the world, we can authoritatively say that spending thousands on a time server could be redundant, unnecessary and a waste of capital if it’s not needed for the application.
How Wi-Fi and PoE Clocks Retrieve Time
Wi-Fi Network clocks and PoE clocks can retrieve accurate time from a variety of secure, reliable sources in order to display the same time on each clock in a building or across a campus.
Power over Ethernet Clocks
PoE clocks are plugged in using a standard Ethernet cable through which they retrieve the correct time from your local area network (LAN) or wide area network (WAN). These networks are either synchronized to a public NTP server beyond your firewall or to an internal source – such as a master clock – on the local intranet. This is an easy and cost-effective way to ensure computers, clocks, and other devices that are connected to the Ethernet all display the same time.
Wi-Fi Network Clocks
Wi-Fi clocks pull time from your existing wireless local area network (WLAN) which is protected behind your firewall. An organization can choose whether this network synchronizes its time via the internet to a public NTP time server beyond the firewall (which comes with some security considerations) or whether the WLAN pulls the time from a master clock or internal server within the firewall. In either case, a specific time server is not required.
Why is a time server potentially unnecessary?
A local time server – purchased and owned by your organization – has its own IP address and sits between your network and the firewall. It provides extremely accurate time via a GPS antenna. This antenna pulls time from GPS satellites and requires a clear view of the sky for best results.
This piece of equipment – which can cost upwards of $7,000 - $10,000 – may be unnecessary for three key reasons.
A time server can be redundant
As noted above, there are multiple ways to pull accurate, secure time from either a public server or an internal server that a company already owns. Purchasing and installing a local time server is redundant because organizations already have various sources for retrieving precise time.
A time server may be overkill
A local time server with a GPS antenna pulls the accurate time down to the nanosecond. This extreme level of precision is often needed by military entities conducting sensitive exercises that require precise coordination; or a company that may preform oceanic navigation calculations; or companies that perform high volume financial trading.
PoE and Wi-Fi clock systems that pull time from an existing Wi-Fi system, the Ethernet, an internal server or a public NTP server are accurate within one-tenth of a second, making them extremely accurate for meetings, classroom changes, shift changes, and other typical office or school activities. For the majority of organizations, this precision is more than adequate. It would be overkill to spend money on a time server.
A time server isn’t the only way to securely pull time
Some organizations choose to open a port through their internet firewall in order for their clocks to contact a public NTP time server on the internet and pull accurate time. The security risk of someone hacking into an organization’s data through this connection is extremely low, but some companies choose not to take that risk and instead use internal processors (any server in your server room); a master clock (for PoE clocks) or the local intranet (for Wi-Fi clocks). This eliminates the need to go through the firewall for synchronized time, keeps the connection secure, and avoids the cost of an unnecessary time server.
Al-Suwaiket saves time and money – without a time server
Al-Suwaiket is a leading Middle East construction company with experience building some of the most critical roads, bridges and buildings in the region. A recent project was the construction of a 55,000 square meter school in Saudi Arabia that spanned four buildings.
Al-Suwaiket contacted several vendors about clock technology systems for the school. After careful evaluation, Al-Suwaiket selected American Time as their clock partner for Wi-Fi and Power over Ethernet (PoE) clocks. One deciding factor that led them to their selection decision was that American Time did not recommend using a time server for their clock systems. Al-Suwaiket determined that using a time server - while recommended by other clock vendors - was more expensive, redundant, and unnecessary to achieve the desired goals of the project.
“We needed a simple and easy-to-maintain and install clock system,” said Don Lewis, director of IT for Al-Suwaiket Dubai. “We purchased 222 American Time Wi-Fi clocks for classrooms and 11 PoE double-sided wall clocks for hallways and common areas…We also opted for Wi-Fi rather than a master clock for ease of installation, as we felt NTP server is just as reliable in a school environment as a mater clock. We simply just set our bell and PA system to the same NTP server address for synchronization.”
Conclusion: Preserve your budget and time
PoE clocks and Wi-Fi network clocks are some of the most popular clock systems because they are an easy, affordable and accurate solution for displaying the same time throughout a building or campus. A time server with GPS-sourced time is simply extra equipment and cost, and something that can easily be avoided.