A cellular phone tower is made of different beams and struts. These are able to withstand tension (pulling) and compression (pushing) forces. They have a wide base that supports them and carries the weight of the rest of the tower.
How Cell Phone Towers Work
Cell Phone Towers (also called Base Stations), have electronic equipment and antennas that send and receive signals to and from cell phones. Antennas may be attached to free-standing towers or structures or may be mounted on non-tower structures such as building rooftops, billboards, or church steeples
What Is Needed To Make A Cellphone Tower?
Image result for cell phone tower grade 7
Your basic list of required components consists of a tower, an outdoor antenna, an indoor antenna, a bi-directional amplifier, and RF cables. For the best performance, make sure that your outdoor antenna is highly directional, essentially a narrow, laser-like beam that points directly to the nearest cell tower.
Union High School’s Grade 7 Technology learners were recently tasked with designing and building a model of a cell phone tower using their knowledge of structures.
The learners were allowed to choose whether or not they would be building a standard cell phone tower or one that would blend in with the environment in order to limit visual pollution.
Seen here are some of their brilliant designs:
GRADE 7 TECHNOLOGY – TASK ONE
Please complete all questions on the exam pad pages. Write the question and the answer.
These pages will be checked and marked and will
then go into your technology file
Structures
Different types of structures.
Describe an eggshell
Shell structures
Shell structures are usually curved, making them very strong structures. The curved shape means that they can take a lot of pressure and stress because the pressure is transferred to the outer edges of the structure.
List other natural and man-made shell structures you can think of.
Frame structures
Frame structures are supported by a“skeleton” of rigid parts rather than load-bearing walls. This makes the structure lighter and stronger. Some frames have a”skin” over them but the strength and support come from the frame structure. Others are open-frame structures like pylons.
Solid structures
These are structures that are not hollow (as in a shell structure) and they don’t have any joints (as in a frame structure). They bear the whole load and are generally strong. They can be made of one type of material (eg. a boulder) or made of several layers of materials “stuck together” (eg. a brick wall)
Can you think of some other examples of solid structures?
Structures
Can you remember what a frame structure is or how it is made?
Look at this picture of a cellular phone tower. What do you notice?
NEW WORDS
Rigid: Stiff or firm and difficult to bend.
Members: Parts (beams of a frame structure that are joined together)
A cellular phone tower is made of different beams and struts. These are able to withstand tension (pulling) and compression (pushing) forces. They have a wide base that supports them and carries the weight of the rest of the tower.
There are two types of members:
1) Tie beams are horizontal beams or cross-pieces. They hold the structure together by “pulling” on the parts. This means that they can withstand tension forces.
2) Strutsarediagonalmembers.Theysupportthestructureandkeepthepieces in position by “pushing” against them. This means they can withstand compression forces.
Grade 7 Term 2 Technology: Structures (investigate a frame structure)
Horizontal
NEW WORDS
Horizontal: Parallel to the horizon, orground.
Diagonal: The line inside a shape joining opposite corners.
Tension force: Force caused by pulling. Compression force: Force caused by pushing.
Dia gon al
GRADE 7
Label the following on the cell phone tower:
*Strut *Tie-beam * Compression force * Tensionforce
Structures
Doyouhaveacellularphone? Doyouhavealandlineathome?
Landlines transmit your voice from your telephone through a network
of cables to
anotherlandlinetelephone.Thesecablescanbeundergroundor suspended in overheadlines.
Mobile or cellular phones use radio waves that transmit your voice and message through a cellular network.
Both have advantages (good things) and disadvantages (bad things). Before we consider these, read the scenario on the left and decide which telephone system would be best to use and give a reason for your answer.
Scenario Telephone Systems Reason
Chichiwantstoremindher momtobuyeggsfromthe supermarket. | ||
Graemeisillsohismom phonestheschooltolet themknowhewon’tbe there. | ||
Tumelo’swatchisbroken; hewonderswhatthetime is. | ||
Coleliveswithhismombut hecallshisdadandspeaks foranhoureveryday. |
Structures
MobileTelephone System | Landline Telephone System |
Easeofcommunication:Youcan communicate easily with anyone, anywhere. As long as theyhave Nolong-distancecharges:There are standard rates whether you are calling someone in Johannesburg or Cape Town. This excludes internationalcalling. Safety / Emergencies: You can always call or text for help no matter where you are. | Reliability: Because they rely on cables to transmit signals, they tend to be more reliable than cellular phones which rely on a network. Emergencies: If you can get to Price: Landline calls are cheaper than cellular phone calls. |
MobileTelephone System | Landline Telephone System |
Interruption: Cellular phones can disrupt and distract you from what you are doing. Safety: Talking or texting on a cellular phone can distract you when you should be paying attention (walking on the street,driving). Service: Bad weather and software problems can cause poor reception or cause the call to bedisconnected. Availability:Some remote areas do not have cellular phonecoverage. | Cable theft: When the cables that transmit the signals are stolen or damaged, your landline won’t work. Mobility: Landlines are fixed and soyouarelimitedtowhereyoucan usethem.Cordlessphonesarestill limited to a certain distance from the handset. Availability:Some remote areas don’t have the infrastructure for telephone lines. Long-distance charges:The price of a call is determined by the distance and duration of the call. |
First, let’s compare some of the advantages of both systems:
Here are some disadvantages of these telephone systems:
Structures |
When designing and constructing structures there are various design issues thatweneedtoconsider.Wehavealreadyconsideredthestructuralelements, reinforcing techniques and stability. These design issues relate to how the structure is constructed or made. Now, we will consider visual pollution (whether or not the structure will be unattractive to the natural environment) and the structures impact on theenvironment.
Visual Pollution
It is important that a structure is not only built well but that it is also attractive. Unattractive structures do not appeal to the eye and so people are opposed to them.
Consider these two pictures of cellular towers.
What do these towers both do?
What is the difference between the two towers?
disguised cellular tower
cellular tower
‘Visual Pollution’ refers to structures or objects that ruin what the natural environment looks like, making it unattractive and unappealing.
Many cellular towers are needed in urban areas. Their appearance is often very structuralandnotatallattractive.Todecreasevisualpollution,manyofthesetowers have been camouflaged astrees.
Impact on the environment
The environment consists of many factors. Can you name a few?
Construction of any structure will affect one or more of these factors, either in a positive or negative way.
Consider this scenario:
A cell phone company wants to extend its coverage into a rural area. The area is predominantlyafarmingcommunitywhereanimals,likegoatsandcattlearekept. The community depends on the local natural resources for food, medicine and for buildinghousesandfences.Allopenlandthatisnotusedforfarmingorhousing,is usedasgrazingland.Thecommunityisveryconcernedaboutpreservingthenatural environmentandnotinterferingwiththeecosystemsthatexistthere.However,they areexcitedthattheywillbeabletocommunicatewithlovedoneswholivefaraway.
Discuss the impact of constructing cellular towers in this rural area.
