Introduction
Over the life of the Palm device which began in 1996 with the Pilot 1000, there have been continuing efforts to improve the performance of data synchronization as well as to provide greater flexibility in connectivity. Initial Palms could only synchronize to a PC using a HotSync cradle connected via serial cable to the COM port on the PC. Drop the Palm into the cradle, hit the HotSync button, and “voila” - you have data synchronizing across the connection to and from your PC! Today there are so many ways to get data from one place to another that the discussion could go on endlessly.
The focus of this analysis will be on 5 common and distinct methods. Each method will be outlined as to how it is implemented, and then each method will be evaluated as to strengths, weaknesses, and cost.All of these methods are usable for solutions requiring multiple users to synchronize to a single enterprise database. However, each of these solutions are discussed and analyzed with the assumption that HotSyncs are consecutive and not concurrent. Multi-user, simultaneous HotSyncs requires replacing the standard HotSync Manager with other software, such as Pumatech’s Enterprise Intellisync Server. Such solutions can have varied hardware requirements and restrictions. This analysis will not consider such multi-user, simultaneous synchronization scenarios.
Current Methods for Analysis
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The following are detailed descriptions of each of these five synchronization methods.
A. Cradle Communication
A standard Microsoft Windows PC (Win98 or higher) is connected to a serial or USB Palm HotSync Cradle. The PC is running the Palm HotSync Manager and is setup to watch for HotSyncs on the serial or USB port, as applicable. The Palm device is placed in the cradle and a button on the cradle is pressed to initiate the Hotsync.
B. Modem Communication
Several vendors, including Palm, produce attachable or plug-in modems for various Palm devices. These modems are connected to any standard analog phone line to dial out from the Palm. Modems call modems, so there is a modem attached to a standard Microsoft Windows PC in the main office. This PC is running the Palm HotSync Manager and is setup to listen for HotSyncs coming in on the modem port. The modem is connected to a dedicated phone line. The Palm user taps the HotSync icon on the screen and the Palm communicates with the attached modem to dial out and connect to the modem in the main office and initiate the HotSync.
C. ISP Communication via Internet
This solution is very similar to option B. The main difference here is that instead of the modem attached to the Palm calling another modem in the main office, the modem calls and connects with an Internet Service Provider’s modem bank. The PC in the main office has the HotSync manager setup to listen for network HotSyncs, and is visible on the internet at a fixed IP address. Once the Palm dials out and connects to the internet, it is able to locate the PC in the main office at its fixed IP address and initiate the Hotsync.
D. 802.11 Communication
Some vendors, including Palm, are now producing Palms with built-in 802.11 wireless capabilities, or with add-on devices that enable 802.11 wireless communications. 802.11 has varied range depending on the amount of power supplied, but current Palms have 802.11 range of around 100 to 200 feet. The Palm must be within range of a wireless access point for communication to occur. 802.11 wireless access points can be installed in company networks, and also exist in a growing number of public areas for wireless internet access. Telecommunications vendors are now implementing widespread 802.11 access to the internet. In any case, once the device is in range of an 802.11 access point, the Palm then locates the PC in the main office by its fixed IP address and initiates the HotSync in the same way as in option C, but at a much higher data rate. Data rates are up to 11 megabits per second.
E. Wireless Communication via Internet
Several telecommunications vendors have implemented high-speed, digital cellular networks called 3G networks. These networks are available almost everywhere that analog cellular networks are available, especially in major cities. These vendors have partnered with hardware manufacturers to produce SmartPhones that include the Palm OS and all of the features of Palm devices. This allows SmartPhones to connect to the internet via the 3G high-speed networks and then locate the PC in the main office by its fixed IP address and initiate the HotSync. Data rates are in the range of 144kbps to 2mbps, about 3 to 30 times the rate of a standard internet dial-up connection.
Comparison of Methods
Each of the methods listed has definite advantages and definite disadvantages. There are several factors that may influence a business to select one or a combination of these methods, and some of these are indicated in the chart below. It is important to note that other factors such as the nature of the software application, the importance of lag time from field activity to main office notification, and the number and types of users can influence this selection process.
Conclusion
At Austin Lane Technologies, Inc. (ALTI), software engineers, programmer/analysts, installers and trainers have collected a vast amount of experience and knowledge about the synchronization options available. Each business and each software solution has unique needs and constraints. It is highly recommended that you consult with experienced developers like ALTI before making final decisions about the synchronization technology for your company.
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