Copyright Goodheart-Willcox Co., Inc. 457 Chapter 14 Wireless Network Security With 5G rollout only recently occurring, there are still many unknowns regarding its security. However, 5G networks are increasingly based on software. Therefore, one important security implication to consider is the development of the 5G software. Flaws related to poor software development could pose a number of risks to the security of 5G. RF Spectrum Cellular networks operate in licensed areas of the RF spectrum. The radio frequency (RF) spectrum is a range of frequencies by which radio waves operate and commu- nicate. Within a given market, mobile carriers cannot transmit or receive data using the same frequencies. Mobile devices transmit a great deal of data, meaning a large spectrum of RF frequencies is desired. With many competing needs, including satel- lite transmissions, managing the spectrum can be a difficult process for the Federal Communications Commission (FCC). The FCC is tasked with freeing up additional space in the spectrum to help increase the amount of unlicensed space used to increase capacity of wireless technologies. To facilitate this task, the FCC offers incentives for television broadcasters to use less of the spectrum. It also returns unused spectrum from other governmental agencies. SIM Cards An important consideration regarding cellular is the reliance on subscriber identity module (SIM) cards. A subscriber identity module (SIM) card is an integrated circuit that stores a cellular device’s international mobile subscriber identity (IMSI) number and related key. Together, an IMSI and its key are used to authenticate cellu- lar subscribers on a given network. Generally, SIM cards are secure, but they can be weaponized in a SIM swap attack. A SIM swap attack is a form of social engineering in which a person convinces a cellular carrier to switch a cellular number to a different SIM card. Once this is accomplished, all phone-based multifactor authentication practices are compro- mised. Unfortunately, in a SIM swap attack, the target does not have a lot of recourse. 2.6 2.6 Actual coverage Tower Area without coverage Theoretical coverage Goodheart-Willcox Publisher Figure 14-7 The coverage provided by the base station is contained within a specified geographic area known as a cell. When a mobile user moves out of one cell, the base station performs a handoff to the next cell.