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IPWireless can operate in either a single 5 MHz channel, a 10 MHz channel, or in pairs of 5MHz or 10MHz channels, with development underway for 15MHz and 20MHz channels. IPWireless has commercial product currently in production for the following bands:
- 450 - 480 MHz
- 850 - 900 MHz
- 1900 - 1920 MHz (IMT-2000 3G band)
- 2010 - 2025 MHz (IMT-2000 3G band)
- 2053 - 2082 MHz
- 2500 - 2690 MHz (BRS band in US, IMT-2000 extension band internationally)
- 3400 - 3600 MHz (international FWA band)
Product is in development for the following additional bands:
- 700 MHz (new US band)
- 2300 - 2400 MHz (China and Korea TDD band, WCS band in US, Australian MMDS band)
Frequency Reuse
The 3GPP UMTS TD-CDMA standard is designed to support n=1 reuse (single frequency network). To be able to support true n=1 reuse, a technology must be able to operate with negative C/I (desired signal below the level of interference / noise). UMTS TD-CDMA achieves this by using direct-sequence spread-spectrum, which provides the processing gain required for negative C/I operation. IPWireless can therefore operate with all cells and sectors on the same frequency.
The UMTS TD-CDMA system adapts dynamically to changing channel conditions, including C/I that is the dominant factor in the throughput achieved in an interference-limited environment. Therefore, while the system operates perfectly with n=1 reuse, average throughputs will be significantly higher if a multiple-frequency reuse is use. A reuse of n=3 with 3-sector sites (1:3 reuse) is commonly used by operators who have sufficient spectrum. Other reuse schemes are also feasible, such as n=2 with 4 sector sites (1:2 reuse. Simulations and trial results show that there is little advantage in reuse greater than n=3, as n=3 performance is similar to the "no interference" case.
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