|
Repair and maintenance services of radio transmitters |
|
|
Repair and maintenance services of radiotelephony apparatus |
|
|
Repair and maintenance services of line telephony and line telegraphy equipment |
|
|
Repair and maintenance services of line telephony equipment |
|
|
Telephone network maintenance services |
|
|
Upgrade services of telephone switching equipment |
|
|
Repair and maintenance services of telephone switching apparatus |
|
|
Repair and maintenance services of telephone sets |
|
|
Repair and maintenance services of line telegraphy equipment |
|
|
Repair and maintenance services of line telex equipment |
|