| ==Phrack Inc.== | |
| Volume Four, Issue Thirty-Eight, File 9 of 15 | |
| *************************************************************************** | |
| * * | |
| * Cellular Telephony * | |
| * * | |
| * by * | |
| * Brian Oblivion * | |
| * * | |
| * * | |
| * Courtesy of: Restricted-Data-Transmissions (RDT) * | |
| * "Truth Is Cheap, But Information Costs." * | |
| * * | |
| * * | |
| *************************************************************************** | |
| The benefit of a mobile transceiver has been the wish of experimenters since | |
| the late 1800's. To have the ability to be reached by another man despite | |
| location, altitude, or depth has had high priority in communication technology | |
| throughout its history. Only until the late 1970's has this been available to | |
| the general public. That is when Bell Telephone (the late Ma Bell) introduced | |
| the Advanced Mobile Phone Service, AMPS for short. | |
| Cellular phones today are used for a multitude of different jobs. They are | |
| used in just plain jibber-jabber, data transfer (I will go into this mode of | |
| cellular telephony in depth later), corporate deals, surveillance, emergencies, | |
| and countless other applications. The advantages of cellular telephony to the | |
| user/phreaker are obvious: | |
| 1. Difficulty of tracking the location of a transceiver (especially if the | |
| transceiver is on the move) makes it very difficult to locate. | |
| 2. Range of the unit within settled areas. | |
| 3. Scrambling techniques are feasible and can be made to provide moderate | |
| security for most transmissions. | |
| 4. The unit, with modification can be used as a bug, being called upon by the | |
| controlling party from anywhere on the globe. | |
| 5. With the right knowledge, one can modify the cellular in both hardware and | |
| software to create a rather diversified machine that will scan, store and | |
| randomly change. | |
| 6. ESN's per call thereby making detection almost impossible. | |
| I feel it will be of great importance for readers to understand the background | |
| of the Cellular phone system, mainly due to the fact that much of the | |
| pioneering systems are still in use today. The first use of a mobile radio | |
| came about in 1921 by the Detroit police department. This system operated at | |
| 2MHz. In 1940, frequencies between 30 and 40MHz were made available too and | |
| soon became overcrowded. The trend of overcrowding continues today. | |
| In 1946, the FCC declared a "public correspondence system" called, or rather | |
| classified as "Domestic Public Land Mobile Radio Service" (DPLMRS) at 35 - 44 | |
| MHz band that ran along the highway between New York and Boston. Now the 35- | |
| 44MHz band is used mainly by Amateur radio hobbyists due to the bands | |
| susceptibility to skip-propagation. | |
| These early mobile radio systems were all PTT (push-to-talk) systems that did | |
| not enjoy today's duplex conversations. The first real mobile "phone" system | |
| was the "Improved Mobile Telephone Service" or the IMTS for short, in 1969. | |
| This system covered the spectrum from 150 - 450MHz, sported automatic channel | |
| selection for each call, eliminated PTT, and allowed the customer to do their | |
| own dialing. From 1969 to 1979 this was the mobile telephone service that | |
| served the public and business community, and it is still used today. | |
| IMTS frequencies used (MHz): | |
| Channel Base Frequency Mobile Frequency | |
| VHF Low Band | |
| ZO 35.26 43.26 | |
| ZF 35.30 43.30 | |
| ZH 35.34 43.34 | |
| ZA 35.42 43.32 | |
| ZY 34.46 43.46 | |
| ZC 35.50 43.50 | |
| ZB 35.54 43.54 | |
| ZW 35.62 43.62 | |
| ZL 35.66 43.66 | |
| VHF High Band | |
| JL 152.51 157.77 | |
| YL 152.54 157.80 | |
| JP 152.57 157.83 | |
| YP 152.60 157.86 | |
| YJ 152.63 157.89 | |
| YK 152.66 157.92 | |
| JS 152.69 157.95 | |
| YS 152.72 157.98 | |
| YA 152.75 158.01 | |
| JK 152.78 158.04 | |
| JA 152.81 158.07 | |
| UHF Band | |
| QC 454.375 459.375 | |
| QJ 454.40 459.40 | |
| QO 454.425 459.425 | |
| QA 454.45 459.45 | |
| QE 454.475 459.475 | |
| QP 454.50 459.50 | |
| QK 454.525 459.525 | |
| QB 454.55 459.55 | |
| QO 454.575 459.575 | |
| QA 454.60 459.60 | |
| QY 454.625 459.625 | |
| QF 454.650 459.650 | |
| VHF high frequencies are the most popular frequencies of all the IMTS band. | |
| VHF low bands are used primarily in rural areas and those with hilly terrain. | |
| UHF bands are primarily used in cities where the VHF bands are overcrowded. | |
| Most large cities will find at least one station being used in their area. | |
| ADVANCED MOBILE PHONE SYSTEM | |
| The next step for mobile telephone was made in 1979 by Bell Telephone, again | |
| introducing the Advanced Mobile Phone Service. This service is the focus of | |
| this document, which has now taken over the mobile telephone industry as the | |
| standard. What brought this system to life were the new digital technologies | |
| of the 1970's. This being large scale integrated custom circuits and | |
| microprocessors. Without these technologies, the system would not have been | |
| economically possible. | |
| The basic elements of the cellular concept have to do with frequency reuse and | |
| cell splitting. | |
| Frequency re-use refers to the use of radio channels on the same carrier | |
| frequency to cover different areas which are separated by a significant | |
| distance. Cell splitting is the ability to split any cell into smaller cells | |
| if the traffic of that cell requires additional frequencies to handle all the | |
| area's calls. These two elements provide the network an opportunity to handle | |
| more simultaneous calls, decrease the transmitters/receivers output/input | |
| wattage/gain and a more universal signal quality. | |
| When the system was first introduced, it was allocated 40MHz in the frequency | |
| spectrum, divided into 666 duplex radio channels providing about 96 channels | |
| per cell for the seven cluster frequency reuse pattern. Cell sites (base | |
| stations) are located in the cells which make up the cellular network. These | |
| cells are usually represented by hexagons on maps or when developing new | |
| systems and layouts. The cell sites contain radio, control, voice frequency | |
| processing and maintenance equipment, as well as transmitting and receiving | |
| antennas. The cell sites are inter-connected by landline with the Mobile | |
| Telecommunications Switching Office (MTSO). | |
| In recent years, the FCC has added 156 frequencies to the cellular bandwidth. | |
| This provides 832 possible frequencies available to each subscriber per cell. | |
| All new cellular telephones are built to accommodate these new frequencies, but | |
| old cellular telephones still work on the system. How does a cell site know if | |
| the unit is old or new? Let me explain. | |
| The problem of identifying a cellular phones age is done by the STATION CLASS | |
| MARK (SCM). This number is 4 bits long and broken down like this: | |
| Bit 1: 0 for 666 channel usage (old) | |
| 1 for 832 channel usage (new) | |
| Bit 2: 0 for a mobile unit (in vehicle) | |
| 1 for voice-activated transmit (for portables) | |
| Bit 3-4: Identify the power class of the unit | |
| Class I 00 = 3.0 watts Continuous Tx's 00XX...DTX <> 1 | |
| Class II 01 = 1.2 watts Discont. Tx's 01XX...DTX = 1 | |
| Class III 10 = 0.6 watts reserved 10XX, 11XX | |
| Reserved 11 = --------- Letters DTX set to 1 permits | |
| use of discontinuous trans- | |
| missions | |
| Cell Sites: How Cellular Telephones Get Their Name | |
| Cell sites, as mentioned above are laid out in a hexagonal type grid. Each | |
| cell is part of a larger cell which is made up of seven cells in the following | |
| fashion: | |
| |---| ||===|| |---| |---| |---| |--- | |
| / \ // \\ / \ / \ / \ / | |
| | |===|| 2 ||===|| ||===|| |---| |---| | |
| \ // \ / \\ // \\ / \ / \ | |
| |---|| 7 |---| 3 ||==|| 2 ||==|| pc |---| |---| | |
| / \\ / \ // \ / \\ Due to the \ | |
| | ||---| 1 |---|| 7 |---| 3 ||--| difficulty of | | |
| \ // \ / \\ / \ // \ representing / | |
| |--|| 6 |---| 4 ||--| 1 |---|| |graphics with | | |
| / \\ / \ // \ / \\ / ASCII characters\ | |
| | ||==|| 5 ||==|| 6 |---| 4 ||--| I will only show | | |
| \ / \\ // \\ / \ // \ two of the cell / | |
| |---| ||===|| ||===|| 5 ||==|| |types I am trying- | |
| / \ / \ / \\ // \ / to convey. \ | |
| | |---| |---| ||==|| |---| |---| | | |
| \ / \ / \ / \ / \ / \ / | |
| |---| |---| |---| |---| |---| |---| | |
| As you can see, each cell is a 1/7th of a larger cell. Where one (1) is the | |
| center cell and two (2) is the cell directly above the center. The other cells | |
| are number around the center cell in a clockwise fashion, ending with seven | |
| (7). The cell sites are equipped with three directional antennas with an RF | |
| beamwidth of 120 degrees providing 360 degree coverage for that cell. Note | |
| that all cells never share a common border. Cells which are next to each other | |
| are obviously never assigned the same frequencies. They will almost always | |
| differ by at least 60 KHz. This also demonstrates the idea behind cell | |
| splitting. One could imagine that the parameter of one of the large cells was | |
| once one cell. Due to a traffic increase, the cell had to be sub-divided to | |
| provide more channels for the subscribers. Note that subdivisions must be made | |
| in factors of seven. | |
| There are also Mobile Cell sites, which are usually used in the transitional | |
| period during the upscaling of a cell site due to increased traffic. Of | |
| course, this is just one of the many uses of this component. Imagine you are | |
| building a new complex in a very remote location. You could feasibly install a | |
| few mobile cellular cell sites to provide a telephone-like network for workers | |
| and executives. The most unique component would be the controller/transceiver | |
| which provides the communications line between the cell site and the MTSO. In | |
| a remote location such a link could very easily be provided via satellite | |
| up/down link facilities. | |
| Let's get into how the phones actually talk with each other. There are several | |
| ways and competitors have still not set an agreed upon standard. | |
| Frequency Division Multiple Access (FDMA) | |
| This is the traditional method of traffic handling. FDMA is a single channel | |
| per carrier analog method of transmitting signals. There has never been a | |
| definite set on the type of modulation to be used. There are no regulations | |
| requiring a party to use a single method of modulation. Narrow band FM, single | |
| sideband AM, digital, and spread-spectrum techniques have all been considered | |
| as a possible standard, but none have yet to be chosen. | |
| FDMA works like this: Cell sites are constantly searching out free channels to | |
| start out the next call. As soon as a call finishes, the channel is freed up | |
| and put on the list of free channels. Or, as a subscriber moves from one cell | |
| to another, the new cell they are in will hopefully have an open channel to | |
| receive the current call in progress and carry it through its location. This | |
| process is called handoff, and will be discussed more in depth further along. | |
| Other proposed traffic handling schemes include Time-Division Multiple Access | |
| (TDMA), Code-Division Multiple Access (CDMA), and Time-Division/Frequency | |
| Division Multiple Access (TD/FDMA). | |
| Time Division Multiple Access | |
| With TDMA, calls are simultaneously held on the same channels, but are | |
| multiplexed between pauses in the conversation. These pauses occur in the way | |
| people talk and think, and the telephone company also injects small delays on | |
| top of the conversation to accommodate other traffic on that channel. This | |
| increase in the length of the usual pause results in a longer amount of time | |
| spent on the call. Longer calls result in higher costs of the calls. | |
| Code Division Multiple Access | |
| This system has been used in mobile military communications for the past 35 | |
| years. This system is digital and breaks up the digitized conversation into | |
| bundles, compresses, sends, then decompresses and converts back into analog. | |
| There are said increases of throughput of 20 : 1 but CDMA is susceptible to | |
| interference which will result in packet retransmission and delays. Of course, | |
| error correction can help in data integrity, but will also result in a small | |
| delay in throughput. | |
| Time-Division/Frequency Division Multiple Access | |
| TD/FDMA is a relatively new system which is an obvious hybrid of FDMA and TDMA. | |
| This system is mainly geared towards the increase of digital transmission over | |
| the cellular network. TD/FDMA make it possible to transmit signals from base | |
| to mobile without disturbing the conversation. With FDMA, there are | |
| significant disturbances during handoff which prevent continual data | |
| transmission from site to site. TD/FDMA makes it possible to transmit control | |
| signals by the same carrier as the data/voice thereby ridding extra channel | |
| usage for control. | |
| Cellular Frequency Usage and channel allocation | |
| There are 832 cellular phone channels which are split into two separate bands. | |
| Band A consists of 416 channels for non-wireline services. Band B consists | |
| equally of 416 channels for wireline services. Each of these channels are | |
| split into two frequencies to provide duplex operation. The lower frequency is | |
| for the mobile unit while the other is for the cell site. 21 channels of each | |
| band are dedicated to "control" channels and the other 395 are voice channels. | |
| You will find that the channels are numbered from 1 to 1023, skipping channels | |
| 800 to 990. | |
| I found these handy-dandy equations that can be used for calculating | |
| frequencies from channels and channels from frequencies. | |
| N = Cellular Channel # F = Cellular Frequency | |
| B = 0 (mobile) or B = 1 (cell site) | |
| CELLULAR FREQUENCIES from CHANNEL NUMBER: | |
| F = 825.030 + B * 45 + ( N + 1 ) * .03 | |
| where: N = 1 to 799 | |
| F = 824.040 + B * 45 + ( N + 1 ) * .03 | |
| where: N = 991 to 1023 | |
| CHANNEL NUMBER from CELLULAR FREQUENCIES | |
| N = 1 + (F - 825.030 - B * 45) / .03 | |
| where: F >= 825.000 (mobile) | |
| or F >= 870.030 (cell site) | |
| N = 991 + (F - 824.040 - B * 45) / .03 | |
| where: F <= 825.000 (mobile) | |
| or F <= 870.000 (base) | |
| Now that you have those frequencies, what can you do with them? Well, for | |
| starters, one can very easily monitor the cellular frequencies with most | |
| hand/base scanners. Almost all scanners pre-1988 have some coverage of the | |
| 800 - 900 MHz band. All scanners can monitor the IMTS frequencies. | |
| Remember that cellular phones operate on a full duplex channel. That means | |
| that one frequency is used for transmission and the other is used for | |
| receiving, each spaced exactly 30 KHz apart. Remember also that the base | |
| frequencies are 45MHz higher than the cellular phone frequencies. This can | |
| obviously make listening rather difficult. One way to listen to both parts of | |
| the conversation would be having two scanners programmed 45 MHz apart to | |
| capture the entire conversation. | |
| The upper UHF frequency spectrum was "appropriated" by the Cellular systems in | |
| the late 1970's. Televisions are still made to receive up to channel 83. This | |
| means that you can receive much of the cellular system on you UHF receiver. One | |
| television channel occupies 6MHz of bandwidth. This was for video, sync, and | |
| audio transmission of the channel. A cellular channel only takes up 24 KHz | |
| plus 3KHz set up as a guard band for each audio signal. This means that 200 | |
| cellular channels can fit into one UHF television channel. If you have an old | |
| black and white television, drop a variable cap in there to increase the | |
| sensitivity of the tuning. Some of the older sets have coarse and fine tuning | |
| knobs. | |
| Some of the newer, smaller, portable television sets are tuned by a variable | |
| resistor. This make modifications MUCH easier, for now all you have to do is | |
| drop a smaller value pot in there and tweak away. I have successfully done | |
| this on two televisions. Most users will find that those who don't live in a | |
| city will have a much better listening rate per call. In the city, the cells | |
| are so damn small that handoff is usually every other minute. Resulting in | |
| chopped conversations. | |
| If you wanted to really get into it, I would suggest you obtain an old | |
| television set with decent tuning controls and remove the RF section out of the | |
| set. You don't want all that hi-voltage circuitry lying around (flyback and | |
| those caps). UHF receivers in televisions downconvert UHF frequencies to IF | |
| (intermediate frequencies) between 41 and 47 MHz. These output IF frequencies | |
| can then be run into a scanner set to pick-up between 41 - 47 MHz. Anyone who | |
| works with RF knows that it is MUCH easier to work with 40MHz signals than | |
| working with 800MHz signals. JUST REMEMBER ONE THING! Isolate the UHF | |
| receiver from your scanner by using a coupling capacitor (0.01 - 0.1 microfarad | |
| <50V minimum> will do nicely). You don't want any of those biasing voltages | |
| creeping into your scanner's receiving AMPLIFIERS! Horrors. Also, don't | |
| forget to ground both the scanner and receiver. | |
| Some systems transmit and receive the same cellular transmission on the base | |
| frequencies. There you can simply hang out on the base frequency and capture | |
| both sides of the conversation. The handoff rate is much higher in high | |
| traffic areas leading the listener to hear short or choppy conversations. At | |
| times you can listen in for 5 to 10 minutes per call, depending on how fast the | |
| caller is moving through the cell site. | |
| TV Cell & Channel Scanner TV Oscillator Band | |
| Channel Freq.& Number Frequency Frequency Limit | |
| =================================================================== | |
| 73 (first) 0001 - 825.03 45.97 871 824 - 830 | |
| 73 (last) 0166 - 829.98 41.02 871 824 - 830 | |
| 74 (first) 0167 - 830.01 46.99 877 830 - 836 | |
| 74 (last) 0366 - 835.98 41.02 877 830 - 836 | |
| 75 (first) 0367 - 836.01 46.99 883 836 - 842 | |
| 75 (last) 0566 - 841.98 41.02 883 836 - 842 | |
| 76 (first) 0567 - 842.01 46.99 889 842 - 848 | |
| 76 (last) 0766 - 847.98 41.02 889 842 - 848 | |
| 77 (first) 0767 - 848.01 46.99 895 848 - 854 | |
| 77 (last) 0799 - 848.97 46.03 895 848 - 854 | |
| All frequencies are in MHz | |
| You can spend hours just listening to cellular telephone conversations, but I | |
| would like to mention that it is illegal to do so. Yes, it is illegal to | |
| monitor cellular telephone conversations. It just another one of those laws | |
| like removing tags off of furniture and pillows. It's illegal, but what the | |
| hell for? At any rate, I just want you to understand that doing the following | |
| is in violation of the law. | |
| Now back to the good stuff. | |
| Conversation is not only what an avid listener will find on the cellular bands. | |
| One will also hear call/channel set-up control data streams, dialing, and other | |
| control messages. At times, a cell site will send out a full request for all | |
| units in its cell to identify itself. The phone will then respond with the | |
| appropriate identification on the corresponding control channel. | |
| Whenever a mobile unit is turned on, even when not placing a call, whenever | |
| there is power to the unit, it transmits its phone number and its 8-digit ID | |
| number. The same process is done when an idling phone passes from one cell to | |
| the other. This process is repeated for as long as there is power to the unit. | |
| This allows the MTSO to "track" a mobile through the network. That is why it | |
| is not a good reason to use a mobile phone from one site. They do have ways of | |
| finding you. And it really is not that hard. Just a bit of RF Triangulation | |
| theory and you're found. However, when the power to the unit is shut off, as | |
| far as the MTSO cares, you never existed in that cell, of course unless your | |
| unit was flagged for some reason. MTSO's are basically just ESS systems | |
| designed for mobile applications. This will be explained later within this | |
| document. | |
| It isn't feasible for the telephone companies to keep track of each customer on | |
| the network. Therefore the MTSO really doesn't know if you are authorized to | |
| use the network or not. When you purchase a cellular phone, the dealer gives | |
| the unit's phone ID number to the local BOC, as well as the number the BOC | |
| assigned to the customer. When the unit is fired up in a cell site its ID | |
| number and phone number are transmitted and checked. If the two numbers are | |
| registered under the same subscriber, then the cell site will allow the mobile | |
| to send and receive calls. If they don't match, then the cell will not allow | |
| the unit to send or receive calls. Hence, the most successful way of | |
| reactivating a cellular phone is to obtain an ID that is presently in use and | |
| modifying your ROM/PROM/EPROM for your specific phone. | |
| RF and AF Specifications: | |
| Everything that you will see from here on out is specifically Industry/FCC | |
| standard. A certain level of compatibility has to be maintained for national | |
| intercommunications, therefore a common set of standards that apply to all | |
| cellular telephones can be compiled and analyzed. | |
| Transmitter Mobiles: audio transmission | |
| - 3 KHz to 15 KHz and 6.1 KHz to 15 KHz. | |
| - 5.9 KHz to 6.1 KHz 35 dB attenuation. | |
| - Above 15 KHz, the attenuation becomes 28 dB. | |
| - All this is required after the modulation limiter and before the | |
| modulation stage. | |
| Transmitters Base Stations: audio transmission | |
| - 3 KHz to 15 KHz. | |
| - Above 15 KHz, attenuation required 28 dB. | |
| - Attenuation after modulation limiter - no notch filter required. | |
| RF attenuation below carrier transmitter: audio transmission | |
| - 20 KHz to 40 KHz, use 26 dB. | |
| - 45 KHz to 2nd harmonic, the specification is 60 dB or 43 + 10 log of | |
| mean output power. | |
| - 12 KHz to 20 KHz, attenuation 117 log f/12. | |
| - 20 KHz to 2nd harmonic, there is a choice: 100 log F/100 or 60 dB or | |
| 43 log + 10 log of mean output power, whichever is less. | |
| Wideband Data | |
| - 20 KHz to 45 KHz, use 26 dB. | |
| - 45 KHz to 90 KHz, use 45 dB. | |
| - 90 KHz to 2nd harmonic, either 60 dB or 43 + 10 log mean output | |
| power. | |
| - all data streams are encoded so that NRZ (non-return-to-zero) binary | |
| ones and zeroes are now zero-to-one and one-to-zero transitions | |
| respectively. Wideband data can then modulate the transmitter | |
| carrier by binary frequency shift keying (BFSK) and ones and zeroes | |
| into the modulator must now be equivalent to nominal peak frequency | |
| deviations of 8 KHz above and below the carrier frequency. | |
| Supervisory Audio Tones | |
| - Save as RF attenuation measurements. | |
| Signaling Tone | |
| - Same as Wideband Data but must be 10 KHz +/- 1 Hz and produce a | |
| nominal frequency deviation of +/- 8 KHz. | |
| The previous information will assist any technophile to modify or even | |
| troubleshoot his/her cellular phone. Those are the working guidelines, as I | |
| stated previously. | |
| UNIT IDENTIFICATION | |
| Each mobile unit is identified by the following sets of numbers. | |
| The first number is the Mobile Identification Number (MIN). This 34 bit binary | |
| number is derived from the unit's telephone number. MIN1 is the last seven | |
| digits of the telephone number and MIN2 is the area code. | |
| For demonstrative purposes, we'll encode 617-637-8687. | |
| Here's how to derive the MIN2 from a standard area code. In this example, 617 | |
| is the area code. All you have to do is first convert to modulo 10 using the | |
| following function. A zero digit would be considered to have a value of 10. | |
| 100(first number) + 10(second) +1(third) - 111 = x | |
| 100(6) + 10(1) + 1(7) - 111 = 506 | |
| (or you could just - 111 from the area code.) | |
| Then convert it to a 10-bit binary number: 0111111010. | |
| To derive MIN1 from the phone number is equally as simple. First | |
| encode the next three digits, 637. | |
| 100(6) + 10(3) + 1(7) - 111 = 526 | |
| Converted to binary: 1000001110 | |
| The remainder of the number 8687, is processed further by taking the | |
| first digit, eight (8) and converting it directly to binary. | |
| 8 = 1000 (binary) | |
| The last three digits are processed as the other two sets of three | |
| numbers were processed. | |
| 100(6) + 10(8) + 1(7) - 111 = 576 | |
| Converted to binary: 1001000000. | |
| So the completed MIN number would look like this: | |
| |--637---||8-||---687--||---617--| | |
| 1000001110100010010000000111111010 | |
| \________/\__/\________/\________/ | |
| A unit is also identifiable by its Electronic Serial Number or ESN. This | |
| number is factory preset and is usually stored in a ROM chip, which is soldered | |
| to the board. It may also be found in a "computer on a chip," which are the | |
| new microcontrollers which have ROM/RAM/microprocessor all in the same package. | |
| This type of set-up usually has the ESN and the software to drive the unit all | |
| in the same chip. This makes is significantly harder to dump, modify and | |
| replace. But it is far from impossible. | |
| The ESN is a 4 byte hex or 11-digit octal number. I have encountered mostly | |
| 11-digit octal numbers on the casing of most cellular phones. The first three | |
| digits represent the manufacturer and the remaining eight digits are the unit's | |
| ESN. | |
| The Station Class Mark (SCM) is also used for station identification by | |
| providing the station type and power output rating. This was already discussed | |
| in a previous section. | |
| The System IDentification (SID number is a number which represents the mobile's | |
| home system. This number is 15-bits long and a list of current nationwide | |
| SID's should either be a part of this file or it will be distributed along with | |
| it. | |
| _______________________________________________________________________________ | |