Radio Frequency Allocation and Assignment PDF

**ALLOCATION VS. ALLOTMENT VS. ASSIGNMENT, AS THEY RELATE TO RADIO FREQUENCIES** **Allocation:** Category/Purpose - Entry in the Table of Frequency Allocations. - Specifies the use of a given frequency band for terrestrial or space radio communication services or radio astronomy under def...

**ALLOCATION VS. ALLOTMENT VS. ASSIGNMENT, AS THEY RELATE TO RADIO FREQUENCIES** **Allocation:** Category/Purpose - Entry in the Table of Frequency Allocations. - Specifies the use of a given frequency band for terrestrial or space radio communication services or radio astronomy under defined conditions. **Allotment:** Geographical Areas - Entry of a designated frequency channel in the ITU\'s agreed plan. - Specifies the use of the channel by one or more nations within certain geographic areas, also under specified conditions. **Assignment:** Assigned Frequency Channel - Authorization given by a nation to a radio station to use a specific radio-frequency channel under particular conditions **ELECTROMAGNETIC SPECTRUM** - The electromagnetic spectrum illustrates the **range of frequencies applicable to electronic communication**. - The **electromagnetic waves are signals that oscillates**. It consists of electric field and magnetic field. It is also characterized by its **amplitude**, **frequency** or **phase**. **FREQUENCY RANGE** **DESIGNATIONS** --------------------- ---------------------------------- 30 Hz to 300 Hz ELF (Extremely Low Frequencies) 300 Hz to 3 kHz VF (Voice Frequencies) 3 kHz to 30 kHz VLF (Very Low Frequencies) 30 kHz to 300 kHz LF (Low Frequencies) 300 kHz to 3 MHz MF (Medium Frequencies) 3 MHz to 30 MHz HF (High Frequencies) 30 MHz to 300 MHz VHF (Very High Frequencies) 300 MHz to 3 GHz UHF (Ultra High Frequencies) 3 GHz to 30 GHz SHF (Super High Frequencies) 30 GHz to 300 GHz EHF (Extremely High Frequencies) 300 GHz to 300 THz Infrared Light 300 THz to 3 PHz Visible Light 3 PHz to 30 PHz Ultraviolet Light 30 PHz to 300 PHz X Rays 300 PHz to 3 EHz Gamma Rays 3EHz to 30 EHz Cosmic rays **WAVEFORM REPRESENTATION** **Definition**: Visualization of signal characteristics over time or frequency. **TYPES**: **1. Time Domain Representation**: Uses an oscilloscope to display amplitude vs. time. **Key parameters:** - **Frequency (f)**: Number of cycles per second (Hz). - **Wavelength (λ)**: Distance between two similar points in a wave (length travelled by one cycle in meters). - **Period (T)**: Time for one complete cycle (reciprocal of frequency). **Relation Between Parameters**: Wavelength, frequency, and period are interrelated; Formula: [\$\\mathbf{\\lambda} = \\frac{c}{f}\\ ;\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\mathbf{f} = \\frac{c}{\\lambda}\\ ;\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\mathbf{T} = \\frac{1}{f}\$]{.math.inline} [**Where:** ]{.math.inline} [**λ** = *wavelength* *in* *meters*]{.math.inline} [**c** = *speed* *of* *light* (3*x*10^8^)]{.math.inline} [**f** = *frequency* *in* *Hz*]{.math.inline} [**T** = *period* *in* *second*]{.math.inline} **Units and Dimensions** [\$\\mathbf{\\text{speed\\ of\\ light}} = 3 \\times 10\^{8}\\frac{m}{\\text{s\\ }}\$]{.math.inline} [\$\\mathbf{\\text{speed\\ of\\ sound}} = 330\\frac{m}{\\text{s\\ }}\$]{.math.inline} **Sample Problems**: 1\. Determine the wavelength of radio waves propagated using a frequency of 30 MHz. **Given:** [**f** = 30 *M*Hz]{.math.inline} **Solution:** [\$\\mathbf{\\lambda} = \\frac{c}{f} = \\frac{3 \\times 10\^{8}}{30 \\times 10\^{6}} = \\mathbf{10}\\mathbf{m}\$]{.math.inline} 2\. If the measured wavelength is 6m, calculate the frequency in MHz. **Given:** [*λ* = 6*m*]{.math.inline} **Solution:** [\$\\ \\mathbf{f} = \\frac{c}{\\lambda}\\ ; = \\frac{3 \\times 10\^{8}}{6} = \\mathbf{50}\\mathbf{\\text{MHz}}\$]{.math.inline} 3\. Find the wavelength of the following frequency: a\. 97.1 MHz b\. 590 kHz c\. 107.5 MHz d\. 2.2 GHz **Solutions:\ a.** [\$\\mathbf{\\lambda} = \\frac{c}{f} = \\frac{3 \\times 10\^{8}}{97.1 \\times 10\^{6}} = \\mathbf{3.09}\\mathbf{m}\$]{.math.inline} **b.** [\$\\mathbf{\\lambda} = \\frac{c}{f} = \\frac{3 \\times 10\^{8}}{590 \\times 10\^{3}} = \\mathbf{508.47}\\mathbf{m}\$]{.math.inline} **c.** [\$\\mathbf{\\lambda} = \\frac{c}{f} = \\frac{3 \\times 10\^{8}}{107.5 \\times 10\^{6}} = \\mathbf{2.79}\\mathbf{m}\$]{.math.inline} **d.** [\$\\mathbf{\\lambda} = \\frac{c}{f} = \\frac{3 \\times 10\^{8}}{2.2 \\times 10\^{9}} = \\mathbf{0.14}\\mathbf{m}\$]{.math.inline} **Note:** The relationship between **wavelength and frequency** is **inversely proportional** to each other. **2. Frequency Domain Representation**: Uses a spectrum analyzer to show amplitude vs. frequency. **Bandwidth (BW)**: The range of frequencies within a signal, calculated as the difference between the highest and lowest frequencies in the spectrum. **Channel Bandwidth**: Portion of the electromagnetic spectrum occupied by a modulated signal. **Measurement**: Calculated as the difference between the highest (f₂) and lowest (f₁) frequencies in a communication channel. **Formula**: [**BW** = *f*~2~ − *f*~1~]{.math.inline} **Common Context**: Often relates to the sidebands of the modulated signal. **Sample Problems:** 1\. Determine the bandwidth of high frequency spectrum. **Given:** [*High* *Frequency* : 3*MHz* − 30*MHz*]{.math.inline} **Solution:** [*BW* = *f*~2~ − *f*~1~]{.math.inline} [*BW* = 30*MHz* − 3*MHz* = **27**MHz]{.math.inline} 2\. Television has a 6 MHz bandwidth. Determine the lower side frequency of channel 2 if the higher frequency is 60 MHz. **Given:** [*BW* = 6MHz]{.math.inline} [*f*~2~ = 60*MHz*]{.math.inline} **Solution:** [*BW* = *f*~2~ − *f*~1~]{.math.inline} [6*MHz* = 60*MHz* − *f*~1~ = **54**MHz]{.math.inline} **Channel:** [**54MHz** **−** **60**MHz]{.math.inline} **TRANSMISSION FACILITIES** 1\. **Narrowband** - Single channel or multiple channels totaling less than wideband (e.g., 64 Kbps). 2\. **Wideband** - Multi-channel capacity ranging from 1.544 Mbps to 45 Mbps (U.S. standards). 3\. **Broadband** - Multi-channel capacity of 45 Mbps or more (U.S. standards). **TRANSMISSION IMPAIRMENTS** **1.** **Attenuation** - Signal loss due to medium resistance. 2\. **Distortion** - Alteration of signal proportions due to system defects. 3\. **Noise** - Corruption of the signal by external (outside) sources (e.g., crosstalk). **CLASSIFICATION OF COMMUNICATIONS** **1. Distress** - Immediate assistance required. 2\. **Urgency** - Requires attention, could escalate. 3\. **Safety** - Meteorological or other safety-related communications **MESSAGE PRIORITIES** 1. Distress calls and traffic. 2. Urgency signals. 3. Safety signals. 4. Radio direction finding communications. 5. Aircraft navigation messages. 6. Ship navigation and weather observation messages. **OPERATIONAL WORDS** +-----------------------------------+-----------------------------------+ | **CODE** | **MEANING** | +===================================+===================================+ | **Roger** | I received your message. | +-----------------------------------+-----------------------------------+ | **Over** | I have completed transmitting and | | | await your reply. | +-----------------------------------+-----------------------------------+ | **Go ahead** | Same as over. | +-----------------------------------+-----------------------------------+ | **Out** | I have completed my communication | | | and do not expect to transmit | | | again. | +-----------------------------------+-----------------------------------+ | **Clear** | I have no further traffic. | | | (Sometimes used in place of Out) | +-----------------------------------+-----------------------------------+ | **Stand by** | Wait for another call or further | | | instructions. | +-----------------------------------+-----------------------------------+ | **Break** | I am changing from one part of | | | the message to another. (Also | | | used to | | | | | | request the received operator to | | | indicate if he has received the | | | portion of the message | | | transmitted thus far.) | +-----------------------------------+-----------------------------------+ | **Copy** | Respond to Break | +-----------------------------------+-----------------------------------+ **INTERNATIONAL PHONETIC ALPHABET** **A** Alpha November **N** ------- --------- ---------- ------- **B** Bravo Oscar **O** **C** Charlie Papa **P** **D** Delta Quebec **G** **E** Echo Romeo **R** **F** Foxtrot Sierra **S** **G** Golf Tango **T** **H** Hotel Uniform **U** **I** India Victor **V** **J** Juliet Whiskey **W** **K** Kilo X-ray **X** **L** Lime Yankee **Y** **M** Mike Zulu **z** **ADDITIONAL NOTES** **ITU vs. NTC vs. FCC** **ITU** (International Telecommunication Union) **Role:** - Sets global telecommunications standards. - Allocates radio frequency spectrum. - Promotes international cooperation in telecommunications development. **NTC** (National Telecommunications Commission) **Role:** - Issues licenses for telecom providers. - Ensures fair competition and consumer protection. - Oversees the implementation of telecommunications laws and policies. **FCC** (Federal Communications Commission) **Role:** - Regulates radio, television, wire, satellite, and cable communications. - Enforces laws related to communications, including consumer protections.