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物联网：通讯技术

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课程 4（共 6 门，Specialization Internet of Things）

Have you wondered how “Things” talk to each other and the cloud? Do you understand the alternatives for conveying latency-sensitive real time data versus reliable signaling data? Building on the skills from the Sensing and Actuation course, we will explore protocols to exchange information between processors. In this course, you will learn how VoIP systems like Skype work and implement your own app for voice calls and text messages. You will start by using the Session Initiation Protocol (SIP) for session management. Next, you will learn how voice codecs such as Adaptive Multi Rate (AMR) are used in 3G networks and use them for voice traffic in your app. Learning Goals: After completing this course, you will be able to: 1. Implement session initiation, management and termination on your DragonBoard™ 410c using SIP. 2. Discover other users and exchange device capabilities. 3. Compare and contrast narrowband and wideband codecs and experience the voice quality differences between them. 4. Implement and demonstrate VoIP calls using the DragonBoard 410c.

从本节课中

Make your own VoIP application

The main part of this module will focus on you making your very own VoIP application on the Android operating system. In order to do this, you might have to brush up on some of the materials in Course 2. You will be required to use Android Studio to push the application onto your board. You will need to know how to use Git, adb and possibly fastboot in order to accomplish this. We will provide you with the code for your application, but remember, the code we are giving you is only a template that can be used to build a bigger and better application with a wide variety of functions. Once we have built your application and pushed it to your board, we will sit together and brainstorm everything we have seen in the last few courses and take a look at what we are now capable of building in the IoT market.

Introduction to Lesson 31:27

VoIP and the Smart Home6:57

VoIP and the Smart Office3:54

Mobile VoIP and EoIP3:42

A look back at Lesson 31:35

与讲师见面

Ganz Chockalingam
Principal Engineer
Qualcomm Institute of Calit2, UC, San Diego
Harinath Garudadri
Associate Research Scientist
Qualcomm Institute of Calit2, UC, San Diego

Now, in the last video we talked to you about making your home smarter, right?

Well, there's also making your office smarter.

Now obviously, there are gonna be a lot of things that are the same,

when you're making your office smarter, making your home smarter.

But there are certain things that might differ because

picture yourself sitting at your desk, and you look around.

There's gonna be certain things on your desk that you use all the time that

you might want to integrate some sensors into, make simpler.

But I also wanted to talk to you

a little bit about the whole VoIP aspect of making your office smarter, right?

So we know that you have these huge companies out there

that take calls all the time, make calls all the time.

International needs where they need to communicate from one

country to another country all the time.

Right, well the old way of doing things cost these companies a lot of money.

>> Right.

>> Now we kind of talked about this already in a previous lesson or module,

but I want to kind of just dive a little deeper, I guess.

VoIP's out now and

you have these companies that all they do is they just pay an Internet bill.

A nice, yeah, nice wide band.

>> Basically, free calling, right?

>> Yeah, basically free calling, right?

So, now, not only can these companies call all these other places that they need

to get a hold of,

but they can also, for instance, I think we talked about this, too.

You want a 24 hour customer service hotline, right?

Well, in the United States, the work days from 9 to 5.

>> Yeah, normally.

>> A normally 8 to 4, 10 to 6, whatever you wanna say.

So 8 hours, whatever.

But then people go home and they go to sleep.

Well, what happens if someone wants to call you at 7 o'clock?

Well, it's the morning time in another country.

So now they could take the calls in another country while

one call center is sleeping, cuz it's night time.

You have to sleep.

Another call center, they're just waking up and starting their job, right?

So this is all done over VoIP.

And you can basically establish connections with your customers 24

hours a day without skipping a beat.

>> RIght.

>> Right, so it's great for international business, but again,

I want to go back to looking around your office and looking around things

that don't exist yet and how you could apply ideas to what's around you.

Now, just talked about a couple things there.

But think about it and apply it.

>> Maybe you can improve.

You have more people in an office than your own house.

So kind of improve interactions amongst the employees.

>> I can just think of one thing.

I know electric bills are really high.

Like even the building we're in, it's outrageous, the electric bills, right?

Well, what if your employees, or

what if you just didn't want to pay that much electricity?

And your employees were overabusing the heater.

>> Yeah.

>> Or abusing the thermostat in general.

Right, well you could control the thermostat from your phone, right?

Or you could monitor the temperature of you building from your phone or

from your home.

>> Or maybe if someone tinkers with the thermostat, you'll get a phone call and

you can yell at whoever's touching it [LAUGH]

>> There you go.

Stop touching the thermostat.

That popped into my head right now.

There's a lot of things that you can do.

And think about sitting at your desk right now, at your office, and

what you could apply to make it more interactive and a smart office.

Stay tuned. See you in the next video.