Wireless communications

Mobile Data Modem

wireless card front

wireless card backside

Qualcomm Gobi is a family of embedded mobile broadband modem products by Qualcomm. One of the more notable products that contain a Gobi modem is the PSVita, which contains a MDM6200™.

Model	Board	ID
PCH1101	ZOE_MP	Qualcomm MDM6200
---	---	---

Point Of Interest: On early manufacture date units (mostly with release firmware such as 1.06) there is a known issue with faulty 3G sub boards. For more information on how to remedy check the errors page: C2-9693-7.

Individual Chipsets	IMT-2000	Modem	Peak Data Rates	Application Processor	Voice	GPS	USB	Wifi
MDM6200	3G	HSPA+, GSM/GPRS/EDGE	Up to 14Mbps	No	Yes	gpsOneGen 8 with GLONASS	USB 2.0 HS Peripheral or Host	Supported with External Wifi

Bluetooth / WiFi

Bluetooth

Bluetooth is a technology for creating personal area networks operating in the 2.4 GHz unlicensed band, with a default range of 10 meters.

An overview of Bluetooth:

• http://engineeringagenda.com/agenda/2013/09/bluetooth/ An introduction to Bluetooth
• http://www.eetimes.com/document.asp?doc_id=1200909 An introduction to debugging Bluetooth in embedded systems

Bluetooth connection

A PSVita can connect up to seven (active) Bluetooth® devices at one time.

There are three type of connections in Bluetooth:

• Single-slave: a point-to-point connection (only 2 Bluetooth units involved)
• Piconet: One Bluetooth unit acts as the master of the piconet, whereas the (up to seven active) others units acts as slaves.
• Scatternet: Multiple piconets with overlapping coverage areas form a scatternet.

Bluetooth radio

Bluetooth 2.0 uses frequencies between 2.4000 and 2.4835 GHz, and divides the band into 79 MHz channels (numbered 0-78), with frequency hopping at a rate of 1600 times per second. Channel 0 has a frequency centred at 2.4020 GHz, allowing a lower guard band of 2 MHz. Channel 78 has a frequency centred at 2.4800 GHz, allowing an upper guard band of 3.5 MHz. Bluetooth devices are divided into three classes, depending on their maximum transmitted power (and hence their maximum range):

Class	Power	Range
Class 1	100mW (20 dBm)	100m (325ft)
Class 2	2.5mW (4 dBm)	10m (32ft)
Class 3	1mW (0 dBm)	1m (3ft)

• http://www.instructables.com/id/Increase-and-extend-the-range-of-a-USB-Bluetooth-d/#step0 Increase and extend the range of a USB Bluetooth

Overlapping channels BT/WiFi

• archaic BT/Wifi channels

Center Frequency (2.4xx Ghz)	BT 2.0 Channel	BT 4.0 Channel	WiFi channel (center freq. in GHz)
00	Guard	Guard
01			1 (2.412)
02	0	0
03	1
04	2	1
05	3
06	4	2		2 (2.417)
07	5
08	6	3
09	7
10	8	4
11	9				3 (2.422)
12	10	5
13	11
14	12	6
15	13
16	14	7				4 (2.427)
17	15
18	16	8
19	17
20	18	9
21	19						5 (2.432)
22	20	10
23	21
24	22	11
25	23
26	24	12	6 (2.437)
27	25
28	26	13
29	27
30	28	14
31	29			7 (2.442)
32	30	15
33	31
34	32	16
35	33
36	34	17			8 (2.447)
37	35
38	36	18
39	37
40	38	19
41	39					9 (2.452)
42	40	20
43	41
44	42	21
45	43
46	44	22					10 (2.457)
47	45
48	46	23
49	47
50	48	24
51	49		11 (2.462)
52	50	25
53	51
54	52	26
55	53
56	54	27		12 (2.467)
57	55
58	56	28
59	57
60	58	29
61	59				13 (2.472)
62	60	30
63	61
64	62	31
65	63
66	64	32
67	65
68	66	33
69	67
70	68	34
71	69
72	70	35
73	71
74	72	36
75	73
76	74	37
77	75
78	76	38
79	77
80	78	39
81	Guard
82		Guard
83

Device icons

Shows the types of found Bluetooth® devices using icons.

Icon	Device
	Wireless controller	No	Yes
	BD Remote Control	No	Yes
	Computer	Yes	Yes
	Mobile phone, smartphone	Yes	Yes
	Headset	Yes	Yes
	Speakers	Yes	Yes
	Mouse	Yes	Yes
	Keyboard	Yes	Yes
	Printer	Yes	Yes
No icon	Other devices	Yes	Yes

Bluetooth Profile

• http://en.wikipedia.org/wiki/List_of_Bluetooth_profiles

Bluetooth® devices that support the following profile can be paired with your system:

• A2DP (Advanced Audio Distribution Profile)
• AVRCP (Audio/Video Remote Control Profile)
• HSP (Headset Profile)
• HID (Human Interface Device Profile)
• HFP (3G model only?), PBAP (3G model only?), PAN (all models?)?

By using the Object Push Profile (OPP), on Firmware 3.18, the attempts forcing the connection to the Vita will give a loophole .

Bluetooth Adressing

Each Bluetooth unit has a unique 48-bit address (BD_ADDR).

Company_assigned						Company_id
Lower Adress Part (24-bit)						Upper Adress Part (8-bit)		Non-Significant Adress Part (16-bit)
lsbxxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxx	xxxxmsb

Class of Device/Service (CoD)

The PlayStation Vita PCH-2000 has a class of Device/Service (CoD) 0x3e0100:

• Major Service Class : Networking (LAN, Ad hoc etc) (0x20000)
• Major Service Class : Rendering (printing, speaker etc) (0x40000)
• Major Service Class : Capturing (scanner, microphone etc) (0x80000)
• Major Service Class : Object Transfer (v-inbox, v-folder etc) (0x100000)
• Major Service Class : Audio (speaker, microphone, headset service etc) (0x200000)

• Major Device Class : Computer (desktop,notebook, PDA, organizers etc ) (0x100)

• Minor Device Class : Uncategorized, code for device not assigned

(Online Generator http://bluetooth-pentest.narod.ru/software/bluetooth_class_of_device-service_generator.html)