900MHz phone freqs ---------------------------------- Panasonic 900MHZ Cordless Freqencies: - CH BASE HANDSET -- ------- ------- 01 902.100 926.100 02 902.130 926.130 03 902.160 926.160 04 902.190 926.190 05 902.220 926.220 06 902.250 926.250 07 902.280 926.280 08 902.310 926.310 09 902.340 926.340 10 902.370 926.370 11 902.400 926.400 ^ ^ ^ 59 903.870 927.870 900 MHZ CORDLESS TELEPHONE FREQUENCIES - - 902 - 928 MHZ NFM Panasonic KX- T9000 (60 Channels) Base 902.100 - 903.870 Base frequencies (30Khz spacing) Handset 926.100 - 927.870 Handset frequencies CH BASE HANDSET CH BASE HANDSET CH BASE HANDSET -- ------- ------- -- ------- ------- -- ------- ------- 01 902.100 926.100 11 902.400 926.400 21 902.700 926.700 02 902.130 926.130 12 902.430 926.430 22 902.730 926.730 03 902.160 926.160 13 902.460 926.460 23 902.760 926.760 04 902.190 926.190 14 902.490 926.490 24 902.790 926.790 05 902.220 926.220 15 902.520 926.520 25 902.820 926.820 06 902.250 926.250 16 902.550 926.550 26 902.850 926.850 07 902.280 926.280 17 902.580 926.580 27 902.880 926.880 08 902.310 926.310 18 902.610 926.610 28 902.910 926.910 09 902.340 926.340 19 902.640 926.640 29 902.940 926.940 10 902.370 926.370 20 902.670 926.670 30 902.970 926.970 CH BASE HANDSET CH BASE HANDSET CH BASE HANDSET -- ------- ------- -- ------- ------- -- ------- ------- 31 903.000 927.000 41 903.300 927.300 51 903.600 927.600 32 903.030 927.030 42 903.330 927.330 52 903.630 927.630 33 903.060 927.060 43 903.360 927.360 53 903.660 927.660 34 903.090 927.090 44 903.390 927.390 54 903.690 927.690 35 903.120 927.120 45 903.420 927.420 55 903.720 927.720 36 903.150 927.150 46 903.450 927.450 56 903.750 927.750 37 903.180 927.180 47 903.480 927.480 57 903.780 927.780 38 903.210 927.210 48 903.510 927.510 58 903.810 927.810 39 903.240 927.240 49 903.540 927.540 59 903.840 927.840 40 903.270 927.270 50 903.570 927.570 60 903.870 927.870 For the single frequency model Panasonic phones, the color of the unit often determines which of the above channels is used by the phone. The following chart lists these allocations. Color of Phone CH BASE HANDSET -------------- -- -------- -------- Blue 01 902.1000 926.1000 Hot Pink 02 902.1300 926.1300 Banana 03 902.1600 926.1600 Cerise 04 902.1900 926.1900 White 05 902.2200 926.2200 Off White 06 902.2500 926.2500 Gray 07 902.2800 926.2800 Fuschia 08 902.3100 926.3100 Shocking Pink 09 902.3400 926.3400 Chartreuse 10 902.3700 926.3700 Neon Purple 11 902.4000 926.4000 Black 59 903.8700 927.8700 V-TECH TROPEZ DX900 (20 CHANNELS) 905.6000 - 907.5000 TRANSPONDER (BASE) FREQUENCIES (100 KHZ SPACING) 925.5000 - 927.4000 HANDSET FREQUENCIES CH BASE HANDSET CH BASE HANDSET CH BASE HANDSET -- ---- ------- -- ---- ------- -- ------- ------- 01 905.6000 925.5000 08 906.3000 926.2000 15 907.0000 926.9000 02 905.7000 925.6000 09 906.4000 926.3000 16 907.1000 927.0000 03 905.8000 925.7000 10 906.5000 926.4000 17 907.2000 927.1000 04 905.9000 925.8000 11 906.6000 926.5000 18 907.3000 927.2000 05 906.0000 925.9000 12 906.7000 926.6000 19 907.4000 927.3000 06 906.1000 926.0000 13 906.8000 926.7000 20 907.5000 927.4000 07 906.2000 926.1000 14 906.9000 926.8000 GE 2-9925 (30 Channels) Base 902.1250 - 903.9850 Base frequencies (60Khz spacing) Handset 926.1250 - 927.9850 Handset frequencies CH BASE HANDSET CH BASE HANDSET CH BASE HANDSET -- -------- -------- -- -------- -------- -- ------ -------- 01 902.1250 926.1250 11 902.7250 926.7250 21 903.3250 927.3250 02 902.1850 926.1850 12 902.7850 926.7850 22 903.3850 927.3850 03 902.2450 926.2450 13 902.8450 926.8450 23 903.4450 927.4450 04 902.3050 926.3050 14 902.9050 926.9050 24 903.5050 927.5050 05 902.3650 926.3650 15 902.9650 926.9650 25 903.5650 927.5650 06 902.4250 926.4250 16 903.0250 927.0250 26 903.6250 927.6250 07 902.4850 926.4850 17 903.0850 927.0850 27 903.6850 927.6850 08 902.5450 926.5450 18 903.1450 927.1450 28 903.7450 927.7450 09 902.6050 926.6050 19 903.2050 927.2050 29 903.8050 927.8050 10 902.6650 926.6650 20 903.2650 927.2650 30 903.8650 927.8650 31 903.9250 927.9250 32 903.9850 927.9850 OTHER 900 MHZ CORDLESS PHONES ------------------------------ AT&T #9120 - - - - - 902.0 - 905.0 & 925.0 - 928.0 MHZ OTRON CORP. #CP-1000 902.1 - 903.9 & 926.1 - 927.9 MHZ SAMSUNG #SP-R912- - - 903.0 & 927.0 MHZ ---------------------------------------------------------------------------- United States Frequencies Early systems used these frequencies for the base units: 1.665, 1.690, 1.695, 1.710, 1.725, 1.730, 1.750, 1.755, 1.770 MHz. And for the handsets: 46.610, 46.630, 46.670, 46.710, 46.730, 46.770, 46.830, 46.870, 46.930, 46.970, 49.670, 49.770, 49.830, 49.845, 49.860, 49.875, 49.890, 49.930, 49.970, 49.990 MHz Both base and handset (portable unit) used frequency modulation. The 1665 kHz, 1690 kHz and 1710 kHz frequencies eventually became part of the expanded AM broadcast band. The second-generation of analog cordless phones were 10-channel FM units operating in the 46.61 MHz to 46.97 MHz (base stations) and 49.67 MHz to 49.99 MHz under Part 15 47 CFR 15.233 using the following frequency pairs. Base Frequency 46.610 MHz - Handset Frequency 49.670 MHz Base Frequency 46.630 MHz - Handset Frequency 49.845 MHz Base Frequency 46.670 MHz - Handset Frequency 49.860 MHz Base Frequency 46.710 MHz - Handset Frequency 49.770 MHz Base Frequency 46.730 MHz - Handset Frequency 49.875 MHz Base Frequency 46.770 MHz - Handset Frequency 49.830 MHz Base Frequency 46.830 MHz - Handset Frequency 49.890 MHz Base Frequency 46.870 MHz - Handset Frequency 49.930 MHz Base Frequency 46.930 MHz - Handset Frequency 49.990 MHz Base Frequency 46.970 MHz - Handset Frequency 49.970 MHz The so-called "49 MHz" cordless phones were rapidly adopted by consumers, resulting in heavy frequency congestion. The 49.830-49.890 MHz frequencies were and still are heavily used by other devices including baby monitors in continuous transmit mode. 15 frequencies were added bringing the total number of channels to 25. 43.71 MHz to 44.49 MHz (43.72 MHz to 44.48 MHz), 46.60 MHz to 46.98 MHz (46.61 MHz to 46.97 MHz), 48.75 MHz to 49.51 MHz (48.76 MHz to 49.50 MHz and 49.66 MHz to 50.0 MHz (49.67 MHz to 4 9.9 MHz). Note that the frequencies overlap with the VHF low band business radio band, the military bands, the 49 MHz RC 49 MHz remote control device frequencies and 49 MHz short range devices (walkie-talkies, baby monitors, etc.) The original 10 channel cordless phones used the 46.6 MHz - 47.0 MHz and 49.6 MHz to 50.0 MHz ranges only (46.610 MHz - 46.970 MHz and 46.670 MHz - 49.990 MHz). The handset/headset transmit frequencies for channels 17, 18, 20, 21 and 22 overlap with the 49.82-49.90 MHz frequencies, including frequencies used by baby monitors. When these cordless phones were popular, issues with interference due to baby monitors was common (and hearing your neighbor's phone call over your baby monitor was also common). 15.233 Operation within the bands 43.71-44.49 MHz, 46.60-46.98 MHz, 48.75- 49.51 MHz and 49.66-50.0 MHz. (a) The provisions shown in this section are restricted to cordless telephones. (b) An intentional radiator used as part of a cordless telephone system shall operate centered on one or more of the following frequency pairs, subject to the following conditions: (1) Frequencies shall be paired as shown below, except that channel pairing for channels one through fifteen may be accomplished by pairing any of the fifteen base transmitter frequencies with any of the fifteen handset transmitter frequencies. Base Frequency 43.720 MHz - Handset Frequency 48.760 MHz - Channel 1 Base Frequency 43.740 MHz - Handset Frequency 48.840 MHz - Channel 2 Base Frequency 43.820 MHz - Handset Frequency 48.860 MHz - Channel 3 Base Frequency 43.840 MHz - Handset Frequency 48.920 MHz - Channel 4 Base Frequency 43.920 MHz - Handset Frequency 49.020 MHz - Channel 5 Base Frequency 43.960 MHz - Handset Frequency 49.080 MHz - Channel 6 Base Frequency 44.120 MHz - Handset Frequency 49.100 MHz - Channel 7 Base Frequency 44.160 MHz - Handset Frequency 49.160 MHz - Channel 8 Base Frequency 44.180 MHz - Handset Frequency 49.200 MHz - Channel 9 Base Frequency 44.200 MHz - Handset Frequency 49.240 MHz - Channel 10 Base Frequency 44.320 MHz - Handset Frequency 49.280 MHz - Channel 11 Base Frequency 44.460 MHz - Handset Frequency 49.360 MHz - Channel 12 Base Frequency 44.400 MHz - Handset Frequency 49.400 MHz - Channel 13 Base Frequency 44.460 MHz - Handset Frequency 49.460 MHz - Channel 14 Base Frequency 44.480 MHz - Handset Frequency 49.500 MHz - Channel 15 Base Frequency 46.610 MHz - Handset Frequency 49.670 MHz - Channel 16 Base Frequency 46.630 MHz - Handset Frequency 49.845 MHz - Channel 17 Base Frequency 46.670 MHz - Handset Frequency 49.860 MHz - Channel 18 Base Frequency 46.710 MHz - Handset Frequency 49.770 MHz - Channel 19 Base Frequency 46.730 MHz - Handset Frequency 49.875 MHz - Channel 20 Base Frequency 46.770 MHz - Handset Frequency 49.830 MHz - Channel 21 Base Frequency 46.830 MHz - Handset Frequency 49.890 MHz - Channel 22 Base Frequency 46.870 MHz - Handset Frequency 49.930 MHz - Channel 23 Base Frequency 46.930 MHz - Handset Frequency 49.990 MHz - Channel 24 Base Frequency 46.970 MHz - Handset Frequency 49.970 MHz - Channel 25 The FCC quickly moved to authorize additional frequency space for cordless phones. With the 900 MHz ISM band 902-928 MHz becoming available next. 900 MHz cordless phones are still used today. Multiple duplex pair analog narrow FM, digital voice and various frequency hopping spread-spectrum or FHSS cordless phones became available for the 900MHz band. If FHSS technology is used, base stations may transmit up to 1 watt ERP. This increase in transmitter power combined with the interference rejection capabilities of spread spectrum gave the higher-end 900 MHz cordless phones significant range. Unlike the older-generation models, 900 MHz cordless telephones never had a standardized channel plan or base and handset frequency pair or channel plan. This meant that manufacturers simply created their own, with widely differing channel steps, number of channels and other options. Even cheap analog FM 900 MHz cordless phones usually featured automatic channel selection. In other words, if the first channel pair was busy the system simply switched to the next clear channel. This same technology was (and is) included in digital voice cordless telephones operating in the 900 MHz band, the 2.4 GHz band and the 5.8 GHz band as well as those using modern DECT technology. The 2.4 GHz band became available shortly after 900 MHz and originally provided excellent results. However, the proliferation of devices operating in the 2.4 GHz band now means that 2.4GHz cordless phones often suffer from (or cause) interference and/or have reduced range compared to the other bands. The 5.8 GHz allocation was opened up to alleviate the congestion on 2.4 GHz. Many 5.8 GHz band cordless phones are sold today. Some "5.8 GHz" phones are actually cross-band and use 5.8 GHz for handset to base but use 900 MHz or 2.4 GHz for base-to-handset. DECT (branded as "DECT 6.0" in the United States and Canada) actually operates in the 1.8 GHz and 1.9 GHz band but provides interference free cordless phone service and is extremely adaptable for business, retail, industrial, office or home use. DECT phone systems may be expanded with numerous base stations, full-duplex intercoms and other systems in a cellular-like network. This includes PBX telephone systems in offices, retail stores, etc. DECT is effectively the convergence of cellular technologies and single-base/single-handset cordless phones.