Is there any way to initiate an SMS MO from a device from the network. Eg: Can I send a special USSD push to a device from the network so that it will SMS a specified text to a specified number from the device.
Only if you are the network operator and the USSD message is defined in the network and supported by the device.
You could also send a MT SMS and get the specified text as a reply (again supported on the device, obviously).
This largely depends on the device capabilities. The device needs logic for processing the USSD message, instead of just displaying it, and to trigger sending the MO SMS.
Since this is not a factory configuration, you would need a custom application to be installed on the device, provided that the device platform allows for the needed functionality. For example some J2ME-capable devices do have this functionality. Consult your device manufacturers development documentation.
Related
I have a BLE device that doesn't respond to SCAN_REQ and am working it out with the vendor independently per https://github.com/espressif/esp-idf/issues/10660.
When I use Nordic nRD Connect iphone app as a client I can see that device in the scan list and can connect to it. However, when I use a different client, a python Windows one, that client doesn't show the device in its scan list and doesn't connect to it if I specify the exact address.
My question is, are BLE 4 devices required to respond to SCAN_REQ requests to be discoverable and connectable or is it just optional response to provide additional advertisement data?
EDIT, I believe that Emil's answer below (thanks) refers to this quote
Yes, it's required to reply with a scan response. That is defined in Bluetooth Core v5.3, Vol 6 Part B (Link Layer), section 4.4.2.3, using the word "shall".
There is one exception though. There is a Filter Accept List in the controller which can contain addresses of centrals allowed to scan and/or connect. There are four combinations the host can set (advertising filter policy) that control if this list shall be used for filtering incoming SCAN_REQ and CONNECT_IND packets, respectively. If you don't use this filtering mechanism, then the device must send a scan response to every scan request.
There are two possible approaches to scanning—Passive Scanning or Active Scanning.
Passive Scanning is when Scanners receive advertising packets and process the contents.
In the case of Active Scanning, however, a device may decide it wants to know more about an advertising device and respond to the initial advertising packet by sending a Scan Request GAP protocol data unit (PDU). This basically means ‘Tell me more.’ The device receiving the Scan Request can send back a Scan Response PDU with more information, once again in the form of a collection of AD types.
The above has been extracted from: https://www.bluetooth.com/blog/advertising-works-part-1/ [the emphasis mine].
Can someone describe the APNs architecture to me in regards to:
How does the handshake work when authenticating from server to client, for a push-notification?
How does the APNs know when to send a push-notification to a phone after it's been turned off (push notification would have been originally sent to the phone at that time). Does the phone know to ping the APNs when it first boots up?
Telecoms is complicated and has evolved over time. An APN is not exactly an internet domain. It is used to establish a PDP context which sets up a tunnel to the home provider to allow packets to be exchanged, this maybe an internet connection. The apn is a name to indicate which network your device is part of, the hlr/hss from the operator will know if your sim is provisioned for that apn. The sim does the mutual authentication between terminal and network, the sim has a identical chip as your payment-card. It contains a secret and logic to verify it knows that secret.
The network can wake up a non-transmitting device, this can be a data-sms, but there is also a signal to send a push to the terminal. The hlr/hss has a message waiting flag indicator, so a switched off device will receive an sms, just one that is processed invisibly and would actually pling on your phone.
As I said, telecoms is complicated so my explanation is more storytelling than reading 3gpp specs.
I have a device which has a settings on it.
The device is uploading data to the cloud.
In the cloud I have settings of the device that I want to do a smart way to update the device settings, but still leave the device the master and stateless. I mean that every request shall come from the device towards the cloud and NACK/ACK will come back to the device.
Currently what we do is to put a command in the database to send to the device according to its serial number. when the device pings to the server, it gets the message with the update. But I do not want to wait for the ping of the BSS. How can I notify the device that a message is waiting for it ?
How do Apple does it with icloud settings to the devices ?
Thanks
Look at the MQTT protocol. This is being promoted by Amazon for IOT devices, and a broker (message router) is available from Amazon. The protocol uses a publish and subscriber model. The devices subscribe to their "topic" something like yourcompany/todevice/serialnumber, and when the server publishes to the same topic, the MQTT broker delivers the message. the messages normally use JSON protocol.
I was wondering if it is possible to send via GSM protocol and appropriate AT commands, few data through a simple GSM call (witout using data traffic).
For example my system is a PIC + GSM Module and it monitors and processes a string of data.
When the user wishes, he makes a voice call in order to interacts with the GSM module via DTMF commands for example via an APP.
My dubt is if the GSM module is able to send the data to thesmartphone in order to monitor the status of the system. The module is a Quectel M95.
During some investigation, I saw that the module can send USSD codes but I don't know if it's possible to customize the USSD and read it from the smartphone as I wish.
Or maybe is it possible to use the FAX for data exchange?
Thanks everybody in advance
Marco
There are a couple of alternatives if you want to avoid using data traffic. But they all require either a connection to a service that is capable of receiving SMS's for example Twilio. Or you can of course have a GSM Module connected to your server which could do the receiving.
You could then send your data and requests for data within an standard SMS body. Or alternatively you could send binary SMS's where you are not limited to the 7 bit character set.
USSD would only work if you have a USSD service provider (I think Twilio has this now). Because the USSD service must initiate a USSD session for your target GSM Module to respond to. USSD code sending for GSM Modules is operator specific and therefore you are limited to what they have implemented (usually for prepaid users and the topping up of accounts).
I have read this somewhere:
Most mobile operators encrypt all mobile communication data, including SMS messages In GSM, messages are encrypted using A5/1 but even when encrypted, the data held by SMS is readable for the operator. Mobile phone operators have the ability to filter and modify short messages during delivery. Also, it is possible that the operator might not filter messages on purpose but might use equipment that cannot handle encrypted messages.
I want to know..is it true..?
Can someone explain how this filtering is done..? and is there any solution to avoid such loss of messages on the network..?
A5/1 is being used on the radio link between mobile and base station controller (BSC, the network entity entity that manages the radio resources). The radio link transports a couple of higher level protocols, among them MAP which is used to transport SMS.
The BSC is relaying SMS over MAP into the core network. The protocol stack between BSC and core network is not encrypted as well as the communication inside the core network. This was deemed as not needed at time GSM was designed, the links are supposed to be mobile operators very own property and territory and therefore assumed being secure.
The core network typically delivers SMS to an SMSC (short message service center) which is reponsible for routing messages to receipients.
A network operator can read SMS in clear text in various places, e.g.
With a protocol analyzer, tapping links between network nodes
On the SMSC, in message queues (databases...) or even log files
On an MSC when tracing MAP messages
Message filtering and modification may happen on the SMSC, depending on the network operator needs.