1. In what ways Yapalong is better than the half-duplex "walkie-talkie"?
  2. Why does Yapalong perform so well among full-duplex radios while keeps relatively low price?
  3. Will I hear lag?
  4. Is Yapalong data transmission encrypted?
  5. What factors would have an impact on the range of communication?
  6. Will adjacent Yapalong groups interfere or pair with each other?
  7. How many Yapalong groups can be contained within one field?
  8. What is “No-master” in Yapalong?
  9. Can filter filter out the noises?
  10. How to use Yapalong for referees in noisy stadium?
  11. Is there any way to increase Yapalong group size and range?

1. Yapalong is superior in a number of ways:
  • .Full Duplex - natural phone-like conversation
  • .Handsfree - no push-to-talk button
  • .Conference mode - not restricted to one talker at a time
  • .Private and secure - no eavesdropping
  • .Efficient power usage - optimized transmit power

2. Most full-duplex radios are digitized. The voice is converted into digital signal and being processed. So is Yapalong. The processing capability of large data determines the performance of a full-duplex radio: range, sound quality, and group size. To improve sound quality and increase group size, we need larger data transmission. On the other hand larger data transmission shortens range.
For the past decade, Nautic Devices Inc. has developed Yapalong IP technology that can compress large data greatly. With this compression capability, the best performance is achieved in all 3 major features: range, sound quality and group size.

3. No. Human ear can detect lag above 100 millisecond while Yapalong has only 30 millisecond lag. Yapalong's superior real-time processing capability keeps the lag very short while enables large group size (8) and wide bandwidth communication.

4.Yes. It is encrypted. Yapalong converts voice into digital (code) form, which is encryption. Furthermore, Yapalong compresses the digital data by Yapalong IP system via both hardware and software before the data are transmitted. The decompression can only be done by Yapalong. The compression can be considered as one more layer of encryption.

5. Buildings, walls, metal, and conductive material has certain effect on RF(radio frequency) transmission. So is human body which is mainly water. We can maximize range by facing the Yapalong unit to the direction of the other party. Wearing the unit on the arm with the Arm Band reduces the effect of the body blockage significantly. Signals from cellphone tower also affects the range. That’s why our range is 300 meters inside city while it can reach as far as 900 meters outside city where cellphone tower signals are weak.

6. No. After proper Binding Procedure (Refer to webpage “Binding Procedure” for details), a unique group ID is generated for each group. Each unit only talks to the units within its group. Every unit identifies other unit by its serial number. Every Yapalong unit bears one unique serial number.

7. Yapalong uses license-free ISM band. However each country/region has different ISM band with different frequency and bandwidth. The number of Yapalong groups depends on the bandwidth of ISM band in your country. Yapalong can divide local ISM band into several channels. And each Yapalong group uses one channel. The number of channels verifies from 2 to 8 channels depending on the country/ region. So the number of groups verifies from 2 to 8 groups within one field.

8. No-master means the whole group is not affected if any unit wonders out of range or is turned off. Yapalong mesh network requires neither base station nor master unit, which makes operation flexible and connection robust. Mesh network can be considered as peer-to-peer. As long as any 2 units of the same group are within range, they are able to communicate. It won’t affect system if any unit wanders out of range. And the connection is automatically resumed if the unit comes back.

9. No. It is common misunderstanding that filter can filter out the noise. Actually filter cannot tell the “good” sound from the “bad” sound, or noise. However filter can set the threshold of the sound level to be received, that is, dynamic range. On Yapalong user can adjust microphone sensitivity to set the sound level to be received by other group users. Yapalong has enough bandwidth to allow wide dynamic range sound.

10. For soccer game officiating in a noisy stadium, the typical setup is as following:
The central referee sets his sensitivity to level 4 (there is total 5 levels of sensitivity in Yapalong) so both ARs (assistant referee) can hear the central referee clearly. ARs set their sensitivity level to 2 and mute their units as much as possible or use PTT(push-to-talk) headsets.

11. Yes. By using audio connector. We can use audio connector to connect multiple units, one unit from each regular group to form large group. 2-8 regular groups can be connected depending on your area. Meanwhile the regular group size is reduced by 1 by this connection. For example, in North America, we can have (8 – 1) x 6 = 42 users.
We can also connect one cellphone with one unit from one group via audio connector. The same can be done for another group. When those 2 cellphones communicate, the 2 remote groups are connected. This way much longer range is realized.