Technology
Questions & Answers:
- Q: Is there any relationship between GCM/OTDM and OTDM optical technology?
A: No. Optical Time Domain Multiplexing is an optical transmission modulation technique used generally over fiber. GCM/OTDM stands from GCM Orthogonal Time Division Multiplexing as this is the main characteristic of this technology: the possibility of transmit simultaneous data flows over the same time interval and the same bandwidth.
- Q: What is GCM/OTDM?
A: GCM/OTDM is a novel modulation and encoding technology that increases the data rates of all wired and wireless communications. GCM/OTDM rate increasing is based on its main powerful advantages: Its QAM Bit Error Rate characteristics, the implicit precise receiver knowledge of the distortion environment (multipath, fading, noise, etc), its simple equalization, its perfect synchronization, and the reduction of the crest factor. By combining these elements, GCM/OTDM delivers data rates orders of magnitude higher than other broadband approaches.
- Q: What is the status of product development?
A: The core research & development underlying GCM/OTDM is complete. The company has jointly developed a working hardware design for the DSL market and it soon will be a product increasing more than a 200% the area of coverage for broadband services, reducing up to 24dB the transmission power and increasing the rate up to 32Mbps in the same bandwidth of ADSL2+. The modulation and demodulation circuitry can be integrated into FPGA or ASIC and will be integrated into equipment such as computers, TV’s, phones, cell phones, base stations, etc. Actually, the company is developing a hardware for the wireless market with the goal of reaching over 300Mbps in the 2.4GHz/5GHz band.
- Q: What government approval is required to operate GCM/OTDM?
A: GCM/OTDM complies with all regulations as it does not modifies the spectrum and even reduces power levels of current applications, this prevent one system from interfering with other's operation.
- Q:What are the difficulties of integrate GCM/OTDM into current communication systems? What about UMTS or CDMA?
A: GCM/OTDM is relatively easy to integrate in any current communication system or application as it does not modify any physical RF nor baseband parameters. Specially for UMTS or CDMA systems, a change in the firmware of base stations is enough to increase the rate of physical layer, reducing power or the number of basestations needed to cover a given area. Obviously, terminals will also have to be modified to add this features.
- Q: What steps have been taken to protect GCM/OTDM?
A: GCM Communications Technology has discretely maintained an Intellectual Property protection program since its inception. GCM Communications Technology has filed several patents related to GCM/OTDM all over the world, covering the basic aspects of transmission, reception, synchronization and equalization.
- Q: What problem does GCM/OTDM solve for wireless applications?
A: As companies scramble to develop 3G telephony and data services, the need to acquire additional radio spectrum has become a pressing issue. The efficiency of modulation technologies is increasing also but slower than demand.
GCM/OTDM solves this problem by reducing the amount of allocated spectrum required to transmit data. GCM/OTDM has a higher efficiency so it can reduce the required spectrum by up to 10 times without changing current hardware platforms.
- Q: What is the implication of using GCM/OTDM in MIMO systems?
A: Main implication of using GCM/OTDM is the precise knowledge of the channel behavior, a fundamental parameter to reach the high rates vaticinated by this techniques.
GCM/OTDM solves this problem by giving the tools to calculate direct and cross antennae channels and then apply it to optimally recover transmitted data.
- Q: What applications can GCM/OTDM be used for?
A: Applications are virtually endless. Initial applications have been focused on high-end markets where a greater present demand exists for high-speed communication solutions, nevertheless new market applications are expected to include, but are not limited to, the following:
- Video on Demand.
- Broadband Internet.
- Beyond 3G.
- Satellite.
- Phones, TV, Radio.
- Wireless LAN.
- Wireless PAN.
- RFID, ZigBee, etc... applications.
- Home Automation/Wireless Appliances.
- DVB, HDTV, DAB – Wireless
- Public Safety Communications (i.e. Police Cars, Fire Trucks, Ambulances, etc).
- RADAR, SONAR, Ecography, In-Vivo .
- Q: What is the BER (bit-error-rate) of GCM/OTDM for different values of SNR?
A: Due to the nature of the GCM/OTDM transmission process, BER figures are exactly the same of perfect equalized QAM. At the same time, its robustness against white or colored noise makes it an optimal technique against it. Obviously, current correction techniques can be applied the same way any QAM system does.
- Q: Does GCM/OTDM require more transmitter power than other technologies?
A: No. In fact since the BER and noise susceptibility performance is excellent, our GCM/OTDM DSL application should use up to 24dB less power than ADSL systems to reach the same rate. This translate to longer battery life and longer range networks for wireless systems.
For more information, please contact us at gcm@gcmcom.com